fplot_core.f90

! fplot_core.f90
 
module fplot_core
    use iso_fortran_env, only : real64, real32, int32
    use iso_c_binding
    use collections
    use strings
    use ferror
    use forcolormap, cmap => colormap ! avoid conflict with the internally defined colormap type
    implicit none
    private
    public :: plot_out_of_memory_error
    public :: plot_invalid_input_error
    public :: plot_invalid_operation_error
    public :: plot_array_size_mismatch_error
    public :: plot_gnuplot_file_error
    public :: gnuplot_terminal_win32
    public :: gnuplot_terminal_wxt
    public :: gnuplot_terminal_qt
    public :: gnuplot_terminal_png
    public :: gnuplot_terminal_latex
    public :: clr_black
    public :: clr_white
    public :: clr_red
    public :: clr_lime
    public :: clr_blue
    public :: clr_yellow
    public :: clr_cyan
    public :: clr_magenta
    public :: clr_silver
    public :: clr_gray
    public :: clr_maroon
    public :: clr_olive
    public :: clr_green
    public :: clr_purple
    public :: clr_teal
    public :: clr_navy
    public :: clr_orange
    public :: marker_plus
    public :: marker_x
    public :: marker_asterisk
    public :: marker_empty_square
    public :: marker_filled_square
    public :: marker_empty_circle
    public :: marker_filled_circle
    public :: marker_empty_triangle
    public :: marker_filled_triangle
    public :: marker_empty_nabla
    public :: marker_filled_nabla
    public :: marker_empty_rhombus
    public :: marker_filled_rhombus
    public :: line_solid
    public :: line_dashed
    public :: line_dotted
    public :: line_dash_dotted
    public :: line_dash_dot_dot
    public :: legend_center
    public :: legend_left
    public :: legend_right
    public :: legend_top
    public :: legend_bottom
    public :: legend_arrange_vertically
    public :: legend_arrange_horizontally
    public :: polar_theta_bottom
    public :: polar_theta_left
    public :: polar_theta_right
    public :: polar_theta_top
    public :: polar_theta_ccw
    public :: polar_theta_cw
    public :: plotdata_max_name_length
    public :: coordinates_cartesian
    public :: coordinates_spherical
    public :: coordinates_cylindrical
    public :: arrow_no_head
    public :: arrow_head
    public :: arrow_backhead
    public :: arrow_heads
    public :: arrow_filled
    public :: arrow_empty
    public :: arrow_no_fill
    public :: arrow_no_border
    public :: linspace
    public :: logspace
    public :: meshgrid
    public :: color
    public :: plot_data
    public :: plot_axis
    public :: terminal
    public :: windows_terminal
    public :: qt_terminal
    public :: wxt_terminal
    public :: png_terminal
    public :: latex_terminal
    public :: legend
    public :: plot
    public :: scatter_plot_data
    public :: plot_data_2d
    public :: plot_2d
    public :: plot_data_3d
    public :: plot_3d
    public :: surface_plot_data
    public :: surface_plot
    public :: colormap
    public :: rainbow_colormap
    public :: hot_colormap
    public :: cool_colormap
    public :: plot_label
    public :: multiplot
    public :: plot_data_error_bars
    public :: plot_data_colored
    public :: plot_data_bar
    public :: plot_data_histogram
    public :: plot_bar
    public :: plot_data_tri_2d
    public :: delaunay_tri_surface
    public :: delaunay_tri_2d
    public :: tri_surface_plot_data
    public :: vector_field_plot_data
    public :: plot_polar
    public :: filled_plot_data
    public :: parula_colormap
    public :: grey_colormap
    public :: earth_colormap
    public :: simplify_polyline
    public :: plot_arrow
    public :: custom_colormap
    public :: cmap
    public :: assignment(=)
    public :: operator(==)
    public :: operator(/=)
 
! ******************************************************************************
! ERROR CODES
! ------------------------------------------------------------------------------
    integer(int32), parameter :: plot_out_of_memory_error = 1000
    integer(int32), parameter :: plot_invalid_input_error = 1001
    integer(int32), parameter :: plot_invalid_operation_error = 1002
    integer(int32), parameter :: plot_array_size_mismatch_error = 1003
    integer(int32), parameter :: plot_gnuplot_file_error = 1004
 
! ******************************************************************************
! GNUPLOT TERMINAL CONSTANTS
! ------------------------------------------------------------------------------
    integer(int32), parameter :: gnuplot_terminal_win32 = 1
    integer(int32), parameter :: gnuplot_terminal_wxt = 2
    integer(int32), parameter :: gnuplot_terminal_qt = 3
    integer(int32), parameter :: gnuplot_terminal_png = 4
    integer(int32), parameter :: gnuplot_terminal_latex = 5
 
! ******************************************************************************
! MARKER CONSTANTS
! ------------------------------------------------------------------------------
    integer(int32), parameter :: marker_plus = 1
    integer(int32), parameter :: marker_x = 2
    integer(int32), parameter :: marker_asterisk = 3
    integer(int32), parameter :: marker_empty_square = 4
    integer(int32), parameter :: marker_filled_square = 5
    integer(int32), parameter :: marker_empty_circle = 6
    integer(int32), parameter :: marker_filled_circle = 7
    integer(int32), parameter :: marker_empty_triangle = 8
    integer(int32), parameter :: marker_filled_triangle = 9
    integer(int32), parameter :: marker_empty_nabla = 10
    integer(int32), parameter :: marker_filled_nabla = 11
    integer(int32), parameter :: marker_empty_rhombus = 12
    integer(int32), parameter :: marker_filled_rhombus = 13
 
! ******************************************************************************
! LINE CONSTANTS
! ------------------------------------------------------------------------------
    integer(int32), parameter :: line_solid = 1
    integer(int32), parameter :: line_dashed = 2
    integer(int32), parameter :: line_dotted = 3
    integer(int32), parameter :: line_dash_dotted = 4
    integer(int32), parameter :: line_dash_dot_dot = 5
 
! ******************************************************************************
! LEGEND CONSTANTS
! ------------------------------------------------------------------------------
    character(len = *), parameter :: legend_top = "top"
    character(len = *), parameter :: legend_center = "center"
    character(len = *), parameter :: legend_left = "left"
    character(len = *), parameter :: legend_right = "right"
    character(len = *), parameter :: legend_bottom = "bottom"
    character(len = *), parameter :: legend_arrange_vertically = "vertical"
    character(len = *), parameter :: legend_arrange_horizontally = "horizontal"
 
! ******************************************************************************
! POLAR PLOT CONSTANTS
! ------------------------------------------------------------------------------
    character(len = *), parameter :: polar_theta_top = "top"
    character(len = *), parameter :: polar_theta_right = "right"
    character(len = *), parameter :: polar_theta_bottom = "bottom"
    character(len = *), parameter :: polar_theta_left = "left"
    character(len = *), parameter :: polar_theta_ccw = "ccw"
    character(len = *), parameter :: polar_theta_cw = "cw"
 
! ******************************************************************************
! COORDINATE SYSTEM CONSTANTS
! ------------------------------------------------------------------------------
    integer(int32), parameter :: coordinates_cartesian = 100
    integer(int32), parameter :: coordinates_spherical = 101
    integer(int32), parameter :: coordinates_cylindrical = 102
 
! ******************************************************************************
! PLOT DATA CONSTANTS
! ------------------------------------------------------------------------------
    integer(int32), parameter :: plotdata_max_name_length = 128
 
! ******************************************************************************
! PRIVATE/DEFAULT CONSTANTS
! ------------------------------------------------------------------------------
    integer(int32), parameter :: gnuplot_default_window_width = 640
    integer(int32), parameter :: gnuplot_default_window_height = 420
    integer(int32), parameter :: gnuplot_max_label_length = 128
    character(len = *), parameter :: gnuplot_default_fontname = "Calibri"
    integer(int32), parameter :: gnuplot_default_font_size = 14
    integer(int32), parameter :: gnuplot_max_path_length = 256
 
! ******************************************************************************
! OPERATORS
! ------------------------------------------------------------------------------
    interface assignment(=)
        module procedure :: clr_assign
        module procedure :: lbl_assign
        module procedure :: par_assign
    end interface
 
    interface operator(==)
        module procedure :: clr_equals
    end interface
 
    interface operator(/=)
        module procedure :: clr_not_equals
    end interface
 
! ******************************************************************************
! BASE TYPES
! ------------------------------------------------------------------------------
    type, abstract :: plot_object
    contains
        procedure(get_string_result), deferred, public :: get_command_string
    end type
 
! ******************************************************************************
! FPLOT_CORE_ROUTINES.F90
! ------------------------------------------------------------------------------
    interface
 
        pure module function linspace(start, finish, npts) result(x)
            real(real64), intent(in) :: start, finish
            integer(int32), intent(in) :: npts
            real(real64), allocatable, dimension(:) :: x
        end function
 
        pure module function logspace(start, finish, npts) result(x)
            real(real64), intent(in) :: start, finish
            integer(int32), intent(in) :: npts
            real(real64), allocatable, dimension(:) :: x
        end function
 
        pure module function meshgrid(x, y) result(xy)
            real(real64), intent(in), dimension(:) :: x, y
            real(real64), allocatable, dimension(:,:,:) :: xy
        end function
    end interface
 
! ******************************************************************************
! FPLOT_COLORS.F90
! ------------------------------------------------------------------------------
    type color
        integer(int32), public :: red = 0
        integer(int32), public :: green = 0
        integer(int32), public :: blue = 255
    contains
        procedure, public, pass :: to_hex_string => clr_to_hex_string
        procedure, public, pass :: copy_from => clr_copy_from
    end type
 
! ------------------------------------------------------------------------------
    interface
        pure module function clr_to_hex_string(this) result(txt)
            class(color), intent(in) :: this
            character(6) :: txt
        end function
 
        pure module subroutine clr_copy_from(this, clr)
            class(color), intent(inout) :: this
            class(color), intent(in) :: clr
        end subroutine
 
        pure module subroutine clr_assign(x, y)
            type(color), intent(out) :: x
            class(color), intent(in) :: y
        end subroutine
 
        pure module function clr_equals(x, y) result(rst)
            type(color), intent(in) :: x, y
            logical :: rst
        end function
 
        pure module function clr_not_equals(x, y) result(rst)
            type(color), intent(in) :: x, y
            logical :: rst
        end function
    end interface
 
! ------------------------------------------------------------------------------
    type(color), parameter :: clr_black = color(0, 0, 0)
    type(color), parameter :: clr_white = color(255, 255, 255)
    type(color), parameter :: clr_red = color(255, 0, 0)
    type(color), parameter :: clr_lime = color(0, 255, 0)
    type(color), parameter :: clr_blue = color(0, 0, 255)
    type(color), parameter :: clr_yellow = color(255, 255, 0)
    type(color), parameter :: clr_cyan = color(0, 255, 255)
    type(color), parameter :: clr_magenta = color(255, 0, 255)
    type(color), parameter :: clr_silver = color(192, 192, 192)
    type(color), parameter :: clr_gray = color(128, 128, 128)
    type(color), parameter :: clr_maroon = color(128, 0, 0)
    type(color), parameter :: clr_olive = color(128, 128, 0)
    type(color), parameter :: clr_green = color(0, 128, 0)
    type(color), parameter :: clr_purple = color(128, 0, 128)
    type(color), parameter :: clr_teal = color(0, 128, 128)
    type(color), parameter :: clr_navy = color(0, 0, 128)
    type(color), parameter :: clr_orange = color(255, 165, 0)
 
    ! A list of colors that can be cycled through by plotting code
    type(color), parameter, dimension(7) :: color_list = [ &
        color(0, int(0.447 * 255), int(0.741 * 255)), &
        color(int(0.85 * 255), int(0.325 * 255), int(0.098 * 255)), &
        color(int(0.929 * 255), int(0.694 * 255), int(0.125 * 255)), &
        color(int(0.494 * 255), int(0.184 * 255), int(0.556 * 255)), &
        color(int(0.466 * 255), int(0.674 * 255), int(0.188 * 255)), &
        color(int(0.301 * 255), int(0.745 * 255), int(0.933 * 255)), &
        color(int(0.635 * 255), int(0.078 * 255), int(0.184 * 255))]
    ! type(color), parameter, dimension(8) :: color_list = [ &
    !     CLR_BLUE, CLR_GREEN, CLR_RED, CLR_CYAN, CLR_LIME, CLR_PURPLE, &
    !     CLR_ORANGE, CLR_BLACK]
 
! ******************************************************************************
! FPLOT_LABEL.F90
! ------------------------------------------------------------------------------
    type, extends(plot_object) :: plot_label
    private
        logical :: m_visible = .true.
        real(real32), dimension(3) :: m_position
        real(real32) :: m_angle = 0.0
        character(len = PLOTDATA_MAX_NAME_LENGTH) :: m_text
    contains
        procedure, public :: get_command_string => lbl_get_cmd
        procedure, public :: get_is_visible => lbl_get_is_visible
        procedure, public :: set_is_visible => lbl_set_is_visible
        procedure, public :: get_position => lbl_get_position
        procedure, public :: set_position => lbl_set_position
        procedure, public :: get_angle => lbl_get_angle
        procedure, public :: set_angle => lbl_set_angle
        procedure, public :: get_text => lbl_get_txt
        procedure, public :: set_text => lbl_set_txt
    end type
 
! ------------------------------------------------------------------------------
    interface
        module function lbl_get_cmd(this) result(x)
            class(plot_label), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        pure module function lbl_get_is_visible(this) result(x)
            class(plot_label), intent(in) :: this
            logical :: x
        end function
 
        module subroutine lbl_set_is_visible(this, x)
            class(plot_label), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function lbl_get_position(this) result(x)
            class(plot_label), intent(in) :: this
            real(real32), dimension(3) :: x
        end function
 
        module subroutine lbl_set_position(this, x)
            class(plot_label), intent(inout) :: this
            real(real32), intent(in), dimension(3) :: x
        end subroutine
 
        pure module function lbl_get_angle(this) result(x)
            class(plot_label), intent(in) :: this
            real(real32) :: x
        end function
 
        module subroutine lbl_set_angle(this, x)
            class(plot_label), intent(inout) :: this
            real(real32), intent(in) :: x
        end subroutine
 
        module function lbl_get_txt(this) result(x)
            class(plot_label), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module subroutine lbl_set_txt(this, x)
            class(plot_label), intent(inout) :: this
            character(len = *), intent(in) :: x
        end subroutine
 
        pure module subroutine lbl_assign(x, y)
            type(plot_label), intent(out) :: x
            class(plot_label), intent(in) :: y
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_ARROW.F90
! ------------------------------------------------------------------------------
    integer(int32), parameter :: arrow_no_head = 0
    integer(int32), parameter :: arrow_head = 1
    integer(int32), parameter :: arrow_backhead = 2
    integer(int32), parameter :: arrow_heads = 3
    integer(int32), parameter :: arrow_filled = 100
    integer(int32), parameter :: arrow_empty = 101
    integer(int32), parameter :: arrow_no_fill = 102
    integer(int32), parameter :: arrow_no_border = 103
 
! ------------------------------------------------------------------------------
    type, extends(plot_object) :: plot_arrow
        ! Determines if the arrow is visible.
        logical, private :: m_visible = .true.
        ! The x, y, z coordinates of the tail
        real(real32), dimension(3) :: m_tail = [0.0, 0.0, 0.0]
        ! The x, y, z coordinates of the head
        real(real32), dimension(3) :: m_head = [0.0, 0.0, 0.0]
        ! The arrow color.
        type(color) :: m_color = clr_black
        ! The line style
        integer(int32) :: m_linestyle = line_solid
        ! The line width
        real(real32) :: m_linewidth = 1.0
        ! The head configuration
        integer(int32) :: m_head_type = arrow_head
        ! Arrow filling
        integer(int32) :: m_filling = arrow_filled
        ! Move to front?
        logical :: m_front = .true.
        ! Arrow head size
        real(real32) :: m_size = 0.375
        ! Arrow head angle
        real(real32) :: m_angle = 10.0
        ! Arrow head back angle
        real(real32) :: m_backangle = 90.0
        ! Use default head size
        logical :: m_use_default_size = .true.
    contains
        procedure, public :: get_is_visible => par_get_is_visible
        procedure, public :: set_is_visible => par_set_is_visible
        procedure, public :: get_tail_location => par_get_tail
        generic, public :: set_tail_location => par_set_tail_1, &
            par_set_tail_2, par_set_tail_3
        procedure, private :: par_set_tail_1
        procedure, private :: par_set_tail_2
        procedure, private :: par_set_tail_3
        procedure, public :: get_head_location => par_get_head
        generic, public :: set_head_location => par_set_head_1, &
            par_set_head_2, par_set_head_3
        procedure, private :: par_set_head_1
        procedure, private :: par_set_head_2
        procedure, private :: par_set_head_3
        procedure, public :: get_color => par_get_color
        procedure, public :: set_color => par_set_color
        procedure, public :: get_line_style => par_get_line_style
        procedure, public :: set_line_style => par_set_line_style
        procedure, public :: get_line_width => par_get_line_width
        procedure, public :: set_line_width => par_set_line_width
        procedure, public :: get_head_type => par_get_head_type
        procedure, public :: set_head_type => par_set_head_type
        procedure, public :: get_head_fill => par_get_fill
        procedure, public :: set_head_fill => par_set_fill
        procedure, public :: get_move_to_front => par_get_move_to_front
        procedure, public :: set_move_to_front => par_set_move_to_front
        procedure, public :: get_head_size => par_get_head_size
        procedure, public :: set_head_size => par_set_head_size
        procedure, public :: get_head_angle => par_get_head_angle
        procedure, public :: set_head_angle => par_set_head_angle
        procedure, public :: get_head_back_angle => par_get_head_back_angle
        procedure, public :: set_head_back_angle => par_set_head_back_angle
        procedure, public :: get_use_default_size => par_get_use_default_size
        procedure, public :: set_use_default_size => par_set_use_default_size
        procedure, public :: get_command_string => par_get_cmd
    end type
 
! ------------------------------------------------------------------------------
    ! fplot_arrow.f90
    interface
        pure module function par_get_is_visible(this) result(rst)
            class(plot_arrow), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine par_set_is_visible(this, x)
            class(plot_arrow), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function par_get_tail(this) result(rst)
            class(plot_arrow), intent(in) :: this
            real(real32), dimension(3) :: rst
        end function
 
        module subroutine par_set_tail_1(this, x)
            class(plot_arrow), intent(inout) :: this
            real(real32), intent(in) :: x(3)
        end subroutine
 
        module subroutine par_set_tail_2(this, x, y)
            class(plot_arrow), intent(inout) :: this
            real(real32), intent(in) :: x, y
        end subroutine
 
        module subroutine par_set_tail_3(this, x, y, z)
            class(plot_arrow), intent(inout) :: this
            real(real32), intent(in) :: x, y, z
        end subroutine
 
        pure module function par_get_head(this) result(rst)
            class(plot_arrow), intent(in) :: this
            real(real32), dimension(3) :: rst
        end function
 
        module subroutine par_set_head_1(this, x)
            class(plot_arrow), intent(inout) :: this
            real(real32), intent(in) :: x(3)
        end subroutine
 
        module subroutine par_set_head_2(this, x, y)
            class(plot_arrow), intent(inout) :: this
            real(real32), intent(in) :: x, y
        end subroutine
 
        module subroutine par_set_head_3(this, x, y, z)
            class(plot_arrow), intent(inout) :: this
            real(real32), intent(in) :: x, y, z
        end subroutine
 
        pure module function par_get_color(this) result(rst)
            class(plot_arrow), intent(in) :: this
            type(color) :: rst
        end function
 
        module subroutine par_set_color(this, x)
            class(plot_arrow), intent(inout) :: this
            type(color), intent(in) :: x
        end subroutine
 
        pure module function par_get_line_style(this) result(rst)
            class(plot_arrow), intent(in) :: this
            integer(int32) :: rst
        end function
 
        module subroutine par_set_line_style(this, x)
            class(plot_arrow), intent(inout) :: this
            integer(int32), intent(in) :: x
        end subroutine
 
        pure module function par_get_line_width(this) result(rst)
            class(plot_arrow), intent(in) :: this
            real(real32) :: rst
        end function
 
        module subroutine par_set_line_width(this, x)
            class(plot_arrow), intent(inout) :: this
            real(real32), intent(in) :: x
        end subroutine
 
        pure module function par_get_head_type(this) result(rst)
            class(plot_arrow), intent(in) :: this
            integer(int32) :: rst
        end function
 
        module subroutine par_set_head_type(this, x)
            class(plot_arrow), intent(inout) :: this
            integer(int32), intent(in) :: x
        end subroutine
 
        module function par_get_cmd(this) result(rst)
            class(plot_arrow), intent(in) :: this
            character(len = :), allocatable :: rst
        end function
 
        pure module function par_get_fill(this) result(rst)
            class(plot_arrow), intent(in) :: this
            integer(int32) :: rst
        end function
 
        module subroutine par_set_fill(this, x)
            class(plot_arrow), intent(inout) :: this
            integer(int32), intent(in) :: x
        end subroutine
 
        pure module function par_get_move_to_front(this) result(rst)
            class(plot_arrow), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine par_set_move_to_front(this, x)
            class(plot_arrow), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function par_get_head_size(this) result(rst)
            class(plot_arrow), intent(in) :: this
            real(real32) :: rst
        end function
 
        module subroutine par_set_head_size(this, x)
            class(plot_arrow), intent(inout) :: this
            real(real32), intent(in) :: x
        end subroutine
 
        pure module function par_get_head_angle(this) result(rst)
            class(plot_arrow), intent(in) :: this
            real(real32) :: rst
        end function
 
        module subroutine par_set_head_angle(this, x)
            class(plot_arrow), intent(inout) :: this
            real(real32), intent(in) :: x
        end subroutine
 
        pure module function par_get_head_back_angle(this) result(rst)
            class(plot_arrow), intent(in) :: this
            real(real32) :: rst
        end function
 
        pure module function par_get_use_default_size(this) result(rst)
            class(plot_arrow), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine par_set_use_default_size(this, x)
            class(plot_arrow), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module subroutine par_set_head_back_angle(this, x)
            class(plot_arrow), intent(inout) :: this
            real(real32), intent(in) :: x
        end subroutine
 
        pure module subroutine par_assign(x, y)
            type(plot_arrow), intent(out) :: x
            class(plot_arrow), intent(in) :: y
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_TERMINAL.F90
! ------------------------------------------------------------------------------
    type, abstract, extends(plot_object) :: terminal
    private
        integer(int32) :: m_windowheight = gnuplot_default_window_height
        integer(int32) :: m_windowwidth = gnuplot_default_window_width
        integer(int32) :: m_termid = 0
        character(len = GNUPLOT_MAX_LABEL_LENGTH) :: m_title = ""
        logical :: m_hastitle = .false.
        character(len = GNUPLOT_MAX_LABEL_LENGTH) :: m_fontname = &
            gnuplot_default_fontname
        integer(int32) :: m_fontsize = gnuplot_default_font_size
    contains
        procedure, public :: get_window_width => term_get_window_width
        procedure, public :: set_window_width => term_set_window_width
        procedure, public :: get_window_height => term_get_window_height
        procedure, public :: set_window_height => term_set_window_height
        procedure, public :: get_command_string => term_get_command_string
        procedure, public :: get_plot_window_number => &
            term_get_plot_window_number
        procedure, public :: set_plot_window_number => &
            term_set_plot_window_number
        procedure, public :: get_title => term_get_title
        procedure, public :: set_title => term_set_title
        procedure, public :: get_font_name => term_get_font_name
        procedure, public :: set_font_name => term_set_font_name
        procedure, public :: get_font_size => term_get_font_size
        procedure, public :: set_font_size => term_set_font_size
        procedure(term_get_string_result), deferred, public :: get_id_string
    end type
 
! ------------------------------------------------------------------------------
    interface
        pure module function term_get_window_width(this) result(x)
            class(terminal), intent(in) :: this
            integer :: x
        end function
 
        module subroutine term_set_window_width(this, x)
            class(terminal), intent(inout) :: this
            integer, intent(in) :: x
        end subroutine
 
        pure module function term_get_window_height(this) result(x)
            class(terminal), intent(in) :: this
            integer :: x
        end function
 
        module subroutine term_set_window_height(this, x)
            class(terminal), intent(inout) :: this
            integer, intent(in) :: x
        end subroutine
 
        pure module function term_get_plot_window_number(this) result(x)
            class(terminal), intent(in) :: this
            integer(int32) :: x
        end function
 
        module subroutine term_set_plot_window_number(this, x)
            class(terminal), intent(inout) :: this
            integer(int32), intent(in) :: x
        end subroutine
 
        module function term_get_title(this) result(str)
            class(terminal), intent(in) :: this
            character(len = :), allocatable :: str
        end function
 
        module subroutine term_set_title(this, txt)
            class(terminal), intent(inout) :: this
            character(len = *), intent(in) :: txt
        end subroutine
 
        module function term_get_font_name(this) result(name)
            class(terminal), intent(in) :: this
            character(len = :), allocatable :: name
        end function
 
        module subroutine term_set_font_name(this, name)
            class(terminal), intent(inout) :: this
            character(len = *), intent(in) :: name
        end subroutine
 
        pure module function term_get_font_size(this) result(sz)
            class(terminal), intent(in) :: this
            integer(int32) :: sz
        end function
 
        module subroutine term_set_font_size(this, sz)
            class(terminal), intent(inout) :: this
            integer(int32), intent(in) :: sz
        end subroutine
 
        module function term_get_command_string(this) result(x)
            class(terminal), intent(in) :: this
            character(len = :), allocatable :: x
        end function
    end interface
 
! ******************************************************************************
! FPLOT_WINDOWS_TERMINAL.F90
! ------------------------------------------------------------------------------
    type, extends(terminal) :: windows_terminal
    private
        character(len = 3) :: m_id = "win"
    contains
        procedure, public :: get_id_string => wt_get_term_string
    end type
 
! ------------------------------------------------------------------------------
    interface
        module function wt_get_term_string(this) result(x)
            class(windows_terminal), intent(in) :: this
            character(len = :), allocatable :: x
        end function
    end interface
 
! ******************************************************************************
! FPLOT_QT_TERMINAL.F90
! ------------------------------------------------------------------------------
    type, extends(terminal) :: qt_terminal
    private
        character(len = 2) :: m_id = "qt"
    contains
        procedure, public :: get_id_string => qt_get_term_string
    end type
 
! ------------------------------------------------------------------------------
    interface
        module function qt_get_term_string(this) result(x)
            class(qt_terminal), intent(in) :: this
            character(len = :), allocatable :: x
        end function
    end interface
 
! ******************************************************************************
! FPLOT_WXT_TERMINAL.F90
! ------------------------------------------------------------------------------
    type, extends(terminal) :: wxt_terminal
    private
        character(len = 3) :: m_id = "wxt"
    contains
        procedure, public :: get_id_string => wxt_get_term_string
    end type
 
! ------------------------------------------------------------------------------
    interface
        module function wxt_get_term_string(this) result(x)
            class(wxt_terminal), intent(in) :: this
            character(len = :), allocatable :: x
        end function
    end interface
 
! ******************************************************************************
! FPLOT_PNG_TERMINAL.F90
! ------------------------------------------------------------------------------
    type, extends(terminal) :: png_terminal
    private
        character(len = 3) :: m_id = "png"
        character(len = GNUPLOT_MAX_PATH_LENGTH) :: m_fname = "default.png"
    contains
        procedure, public :: get_filename => png_get_filename
        procedure, public :: set_filename => png_set_filename
        procedure, public :: get_id_string => png_get_term_string
        procedure, public :: get_command_string => png_get_command_string
    end type
 
! ------------------------------------------------------------------------------
    interface
        module function png_get_term_string(this) result(x)
            class(png_terminal), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function png_get_filename(this) result(txt)
            class(png_terminal), intent(in) :: this
            character(len = :), allocatable :: txt
        end function
 
        module subroutine png_set_filename(this, txt)
            class(png_terminal), intent(inout) :: this
            character(len = *), intent(in) :: txt
        end subroutine
 
        module function png_get_command_string(this) result(x)
            class(png_terminal), intent(in) :: this
            character(len = :), allocatable :: x
        end function
    end interface
 
! ******************************************************************************
! FPLOT_LATEX.F90
! ------------------------------------------------------------------------------
    type, extends(terminal) :: latex_terminal
    private
        character(len = 14) :: m_id = "epslatex color"
        character(len = GNUPLOT_MAX_PATH_LENGTH) :: m_fname = "default.tex"
    contains
        procedure, public :: get_filename => tex_get_filename
        procedure, public :: set_filename => tex_set_filename
        procedure, public :: get_id_string => tex_get_term_string
        procedure, public :: get_command_string => tex_get_command_string
    end type
 
! ------------------------------------------------------------------------------
    interface
        module function tex_get_term_string(this) result(x)
            class(latex_terminal), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function tex_get_filename(this) result(txt)
            class(latex_terminal), intent(in) :: this
            character(len = :), allocatable :: txt
        end function
 
        module subroutine tex_set_filename(this, txt)
            class(latex_terminal), intent(inout) :: this
            character(len = *), intent(in) :: txt
        end subroutine
 
        module function tex_get_command_string(this) result(x)
            class(latex_terminal), intent(in) :: this
            character(len = :), allocatable :: x
        end function
    end interface
 
! ******************************************************************************
! FPLOT_PLOT_DATA.F90
! ------------------------------------------------------------------------------
    type, abstract, extends(plot_object) :: plot_data
    private
        character(len = PLOTDATA_MAX_NAME_LENGTH) :: m_name = ""
    contains
        procedure, public :: get_name => pd_get_name
        procedure, public :: set_name => pd_set_name
        procedure(pd_get_string_result), deferred, public :: get_data_string
    end type
 
! ------------------------------------------------------------------------------
    interface
        pure module function pd_get_name(this) result(txt)
            class(plot_data), intent(in) :: this
            character(len = :), allocatable :: txt
        end function
 
        module subroutine pd_set_name(this, txt)
            class(plot_data), intent(inout) :: this
            character(len = *), intent(in) :: txt
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_PLOT_DATA_COLORED.F90
! ------------------------------------------------------------------------------
    type, abstract, extends(plot_data) :: plot_data_colored
    private
        type(color) :: m_color = clr_blue
        logical :: m_useautocolor = .true.
        integer(int32) :: m_colorindex = 1
    contains
        procedure, public :: get_line_color => pdc_get_line_color
        procedure, public :: set_line_color => pdc_set_line_color
        procedure, private :: get_color_index => pdc_get_color_index
        procedure, private :: set_color_index => pdc_set_color_index
    end type
 
! ------------------------------------------------------------------------------
    interface
        pure module function pdc_get_line_color(this) result(x)
            class(plot_data_colored), intent(in) :: this
            type(color) :: x
        end function
 
        module subroutine pdc_set_line_color(this, x)
            class(plot_data_colored), intent(inout) :: this
            type(color), intent(in) :: x
        end subroutine
 
        pure module function pdc_get_color_index(this) result(x)
            class(plot_data_colored), intent(in) :: this
            integer(int32) :: x
        end function
 
        module subroutine pdc_set_color_index(this, x)
            class(plot_data_colored), intent(inout) :: this
            integer(int32), intent(in) :: x
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_PLOT_AXIS.F90
! ------------------------------------------------------------------------------
    type, abstract, extends(plot_object) :: plot_axis
    private
        logical :: m_hastitle = .false.
        character(len = PLOTDATA_MAX_NAME_LENGTH) :: m_title = ""
        logical :: m_autoscale = .true.
        real(real64), dimension(2) :: m_limits = [0.0d0, 1.0d0]
        logical :: m_logscale = .false.
        logical :: m_zeroaxis = .false.
        real(real32) :: m_axiswidth = 1.0
        ! ADDED March 29, 2023 - JAC
        logical :: m_defaultticlabels = .true.
        character(len = PLOTDATA_MAX_NAME_LENGTH) :: m_ticlabelfmt = "%g"
    contains
        procedure, public :: get_title => pa_get_title
        procedure, public :: set_title => pa_set_title
        procedure, public :: is_title_defined => pa_has_title
        procedure, public :: get_autoscale => pa_get_autoscale
        procedure, public :: set_autoscale => pa_set_autoscale
        procedure, public :: get_limits => pa_get_axis_limits
        procedure, public :: set_limits => pa_set_axis_limits
        procedure, public :: get_is_log_scaled => pa_get_log_scale
        procedure, public :: set_is_log_scaled => pa_set_log_scale
        procedure, public :: get_command_string => pa_get_cmd_string
        procedure, public :: get_zero_axis => pa_get_zero_axis
        procedure, public :: set_zero_axis => pa_set_zero_axis
        procedure, public :: get_zero_axis_line_width => pa_get_zero_axis_width
        procedure, public :: set_zero_axis_line_width => pa_set_zero_axis_width
        procedure(pa_get_string_result), deferred, public :: get_id_string
 
        procedure, public :: get_use_default_tic_label_format => &
            pa_get_use_dft_tic_lbl_fmt
        procedure, public :: set_use_default_tic_label_format => &
            pa_set_use_dft_tic_lbl_fmt
        procedure, public :: get_tic_label_format => pa_get_tic_label_fmt
        procedure, public :: set_tic_label_format => pa_set_tic_label_fmt
    end type
 
! ------------------------------------------------------------------------------
    interface
        module function pa_get_title(this) result(txt)
            class(plot_axis), intent(in) :: this
            character(len = :), allocatable :: txt
        end function
 
        module subroutine pa_set_title(this, txt)
            class(plot_axis), intent(inout) :: this
            character(len = *), intent(in) :: txt
        end subroutine
 
        pure module function pa_has_title(this) result(x)
            class(plot_axis), intent(in) :: this
            logical :: x
        end function
 
        pure module function pa_get_autoscale(this) result(x)
            class(plot_axis), intent(in) :: this
            logical :: x
        end function
 
        module subroutine pa_set_autoscale(this, x)
            class(plot_axis), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function pa_get_axis_limits(this) result(x)
            class(plot_axis), intent(in) :: this
            real(real64), dimension(2) :: x
        end function
 
        module subroutine pa_set_axis_limits(this, lower, upper)
            class(plot_axis), intent(inout) :: this
            real(real64), intent(in) :: lower, upper
        end subroutine
 
        pure module function pa_get_log_scale(this) result(x)
            class(plot_axis), intent(in) :: this
            logical :: x
        end function
 
        module subroutine pa_set_log_scale(this, x)
            class(plot_axis), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module function pa_get_cmd_string(this) result(txt)
            class(plot_axis), intent(in) :: this
            character(len = :), allocatable :: txt
        end function
 
        pure module function pa_get_zero_axis(this) result(x)
            class(plot_axis), intent(in) :: this
            logical :: x
        end function
 
        module subroutine pa_set_zero_axis(this, x)
            class(plot_axis), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function pa_get_zero_axis_width(this) result(x)
            class(plot_axis), intent(in) :: this
            real(real32) :: x
        end function
 
        module subroutine pa_set_zero_axis_width(this, x)
            class(plot_axis), intent(inout) :: this
            real(real32), intent(in) :: x
        end subroutine
 
        pure module function pa_get_use_dft_tic_lbl_fmt(this) result(rst)
            class(plot_axis), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine pa_set_use_dft_tic_lbl_fmt(this, x)
            class(plot_axis), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function pa_get_tic_label_fmt(this) result(rst)
            class(plot_axis), intent(in) :: this
            character(len = :), allocatable :: rst
        end function
 
        module subroutine pa_set_tic_label_fmt(this, x)
            class(plot_axis), intent(inout) :: this
            character(len = *), intent(in) :: x
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_LEGEND.F90
! ------------------------------------------------------------------------------
    type, extends(plot_object) :: legend
    private
        logical :: m_inside = .true.
        logical :: m_box = .true.
        character(len = 20) :: m_horzposition = legend_right
        character(len = 20) :: m_vertposition = legend_top
        logical :: m_show = .false.
        character(len = 20) :: m_layout = legend_arrange_vertically
        logical :: m_opaque = .true.
    contains
        procedure, public :: get_draw_inside_axes => leg_get_inside
        procedure, public :: set_draw_inside_axes => leg_set_inside
        procedure, public :: get_draw_border => leg_get_box
        procedure, public :: set_draw_border => leg_set_box
        procedure, public :: get_horizontal_position => leg_get_horz_pos
        procedure, public :: set_horizontal_position => leg_set_horz_pos
        procedure, public :: get_vertical_position => leg_get_vert_pos
        procedure, public :: set_vertical_position => leg_set_vert_pos
        procedure, public :: get_is_visible => leg_get_visible
        procedure, public :: set_is_visible => leg_set_visible
        procedure, public :: get_command_string => leg_get_command_txt
        procedure, public :: get_layout => leg_get_layout
        procedure, public :: set_layout => leg_set_layout
        procedure, public :: get_is_opaque => leg_get_opaque
        procedure, public :: set_is_opaque => leg_set_opaque
    end type
 
! ------------------------------------------------------------------------------
    interface
        pure module function leg_get_inside(this) result(x)
            class(legend), intent(in) :: this
            logical :: x
        end function
 
        module subroutine leg_set_inside(this, x)
            class(legend), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function leg_get_box(this) result(x)
            class(legend), intent(in) :: this
            logical :: x
        end function
 
        module subroutine leg_set_box(this, x)
            class(legend), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module function leg_get_horz_pos(this) result(x)
            class(legend), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module subroutine leg_set_horz_pos(this, x)
            class(legend), intent(inout) :: this
            character(len = *), intent(in) :: x
        end subroutine
 
        module function leg_get_vert_pos(this) result(x)
            class(legend), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module subroutine leg_set_vert_pos(this, x)
            class(legend), intent(inout) :: this
            character(len = *), intent(in) :: x
        end subroutine
 
        pure module function leg_get_visible(this) result(x)
            class(legend), intent(in) :: this
            logical :: x
        end function
 
        module subroutine leg_set_visible(this, x)
            class(legend), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module function leg_get_command_txt(this) result(txt)
            class(legend), intent(in) :: this
            character(len = :), allocatable :: txt
        end function
 
        pure module function leg_get_layout(this) result(rst)
            class(legend), intent(in) :: this
            character(len = :), allocatable :: rst
        end function
 
        module subroutine leg_set_layout(this, x)
            class(legend), intent(inout) :: this
            character(len = *), intent(in) :: x
        end subroutine
 
        pure module function leg_get_opaque(this) result(rst)
            class(legend), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine leg_set_opaque(this, x)
            class(legend), intent(inout) :: this
            logical :: x
        end subroutine
    end interface
 
 
! ******************************************************************************
! FPLOT_COLORMAP.F90
! ------------------------------------------------------------------------------
    type, abstract, extends(plot_object) :: colormap
    private
        character(len = :), allocatable :: m_label
        logical :: m_horizontal = .false.
        logical :: m_drawborder = .true.
        logical :: m_showtics = .true.
    contains
        procedure, public :: get_command_string => cm_get_cmd
        procedure(cm_get_string_result), deferred, public :: get_color_string
        procedure, public :: get_label => cm_get_label
        procedure, public :: set_label => cm_set_label
        procedure, public :: get_horizontal => cm_get_horizontal
        procedure, public :: set_horizontal => cm_set_horizontal
        procedure, public :: get_draw_border => cm_get_draw_border
        procedure, public :: set_draw_border => cm_set_draw_border
        procedure, public :: get_show_tics => cm_get_show_tics
        procedure, public :: set_show_tics => cm_set_show_tics
    end type
 
! ------------------------------------------------------------------------------
    type, extends(colormap) :: rainbow_colormap
    contains
        procedure, public :: get_color_string => rcm_get_clr
    end type
 
! ------------------------------------------------------------------------------
    type, extends(colormap) :: hot_colormap
    contains
        procedure, public :: get_color_string => hcm_get_clr
    end type
 
! ------------------------------------------------------------------------------
    type, extends(colormap) :: cool_colormap
    contains
        procedure, public :: get_color_string => ccm_get_clr
    end type
 
! ------------------------------------------------------------------------------
    type, extends(colormap) :: parula_colormap
    contains
        procedure, public :: get_color_string => pcm_get_clr
    end type
 
! ------------------------------------------------------------------------------
    type, extends(colormap) :: grey_colormap
    contains
        procedure, public :: get_color_string => gcm_get_clr
    end type
 
! ------------------------------------------------------------------------------
    type, extends(colormap) :: earth_colormap
    contains
        procedure, public :: get_color_string => ecm_get_clr
    end type
 
! ------------------------------------------------------------------------------
    type, extends(colormap) :: custom_colormap
        class(cmap), private, pointer :: m_map => null()
    contains
        final :: custom_final
        procedure, public :: get_color_string => custom_get_clr
        procedure, public :: set_colormap => custom_set
        procedure, public :: get_colormap => custom_get
    end type
 
! ------------------------------------------------------------------------------
    interface
        module function cm_get_cmd(this) result(x)
            class(colormap), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        pure module function cm_get_label(this) result(rst)
            class(colormap), intent(in) :: this
            character(len = :), allocatable :: rst
        end function
 
        module subroutine cm_set_label(this, x)
            class(colormap), intent(inout) :: this
            character(len = *), intent(in) :: x
        end subroutine
 
        pure module function cm_get_horizontal(this) result(rst)
            class(colormap), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine cm_set_horizontal(this, x)
            class(colormap), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function cm_get_draw_border(this) result(rst)
            class(colormap), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine cm_set_draw_border(this, x)
            class(colormap), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function cm_get_show_tics(this) result(rst)
            class(colormap), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine cm_set_show_tics(this, x)
            class(colormap), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        ! --------------------
 
        module function rcm_get_clr(this) result(x)
            class(rainbow_colormap), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        ! --------------------
 
        module function hcm_get_clr(this) result(x)
            class(hot_colormap), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        ! --------------------
 
        module function ccm_get_clr(this) result(x)
            class(cool_colormap), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        ! --------------------
 
        module function pcm_get_clr(this) result(x)
            class(parula_colormap), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        ! --------------------
 
        module function gcm_get_clr(this) result(x)
            class(grey_colormap), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        ! --------------------
 
        module function ecm_get_clr(this) result(x)
            class(earth_colormap), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        ! --------------------
        module function custom_get_clr(this) result(x)
            class(custom_colormap), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        ! --------------------
        module subroutine custom_set(this, map, err)
            class(custom_colormap), intent(inout) :: this
            class(cmap), intent(in) :: map
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        ! --------------------
        module function custom_get(this) result(rst)
            class(custom_colormap), intent(in) :: this
            class(cmap), pointer :: rst
        end function
 
        ! --------------------
        module subroutine custom_final(this)
            type(custom_colormap), intent(inout) :: this
        end subroutine
 
        ! --------------------
    end interface
 
! ******************************************************************************
! FPLOT_PLOT.F90
! ------------------------------------------------------------------------------
    type, extends(plot_object) :: plot
    private
        character(len = PLOTDATA_MAX_NAME_LENGTH) :: m_title = ""
        logical :: m_hastitle = .false.
        class(terminal), pointer :: m_terminal => null()
        type(list) :: m_data
        type(legend), pointer :: m_legend => null()
        logical :: m_showgrid = .true.
        logical :: m_ticsin = .true.
        logical :: m_drawborder = .true.
        type(list) :: m_labels ! Added 6/22/2018, JAC
        integer(int32) :: m_colorindex = 1
        logical :: m_axisequal = .false.
        class(colormap), pointer :: m_colormap
        logical :: m_showcolorbar = .true.
        type(list) :: m_arrows ! Added 1/3/2024, JAC
    contains
        procedure, public :: free_resources => plt_clean_up
        procedure, public :: initialize => plt_init
        procedure, public :: get_title => plt_get_title
        procedure, public :: set_title => plt_set_title
        procedure, public :: is_title_defined => plt_has_title
        procedure, public :: get_legend => plt_get_legend
        procedure, public :: get_count => plt_get_count
        procedure, public :: push => plt_push_data
        procedure, public :: pop => plt_pop_data
        procedure, public :: clear_all => plt_clear_all
        procedure, public :: get => plt_get
        procedure, public :: set => plt_set
        procedure, public :: get_terminal => plt_get_term
        procedure, public :: get_show_gridlines => plt_get_show_grid
        procedure, public :: set_show_gridlines => plt_set_show_grid
        procedure, public :: draw => plt_draw
        procedure, public :: save_file => plt_save
        procedure, public :: get_font_name => plt_get_font
        procedure, public :: set_font_name => plt_set_font
        procedure, public :: get_font_size => plt_get_font_size
        procedure, public :: set_font_size => plt_set_font_size
        procedure, public :: get_tics_inward => plt_get_tics_in
        procedure, public :: set_tics_inward => plt_set_tics_in
        procedure, public :: get_draw_border => plt_get_draw_border
        procedure, public :: set_draw_border => plt_set_draw_border
        procedure, public :: push_label => plt_push_label
        procedure, public :: pop_label => plt_pop_label
        procedure, public :: get_label => plt_get_label
        procedure, public :: set_label => plt_set_label
        procedure, public :: get_label_count => plt_get_label_count
        procedure, public :: clear_all_labels => plt_clear_labels
        procedure, public :: get_axis_equal => plt_get_axis_equal
        procedure, public :: set_axis_equal => plt_set_axis_equal
        procedure, public :: get_colormap => plt_get_colormap
        procedure, public :: set_colormap => plt_set_colormap
        procedure, public :: get_show_colorbar => plt_get_show_colorbar
        procedure, public :: set_show_colorbar => plt_set_show_colorbar
        procedure, public :: get_command_string => plt_get_cmd
        procedure, public :: push_arrow => plt_push_arrow
        procedure, public :: pop_arrow => plt_pop_arrow
        procedure, public :: get_arrow => plt_get_arrow
        procedure, public :: set_arrow => plt_set_arrow
        procedure, public :: get_arrow_count => plt_get_arrow_count
        procedure, public :: clear_arrows => plt_clear_arrows
    end type
 
! ------------------------------------------------------------------------------
    interface
        module subroutine plt_clean_up(this)
            class(plot), intent(inout) :: this
        end subroutine
 
        module subroutine plt_init(this, term, fname, err)
            class(plot), intent(inout) :: this
            integer(int32), intent(in), optional :: term
            character(len = *), intent(in), optional :: fname
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module function plt_get_title(this) result(txt)
            class(plot), intent(in) :: this
            character(len = :), allocatable :: txt
        end function
 
        module subroutine plt_set_title(this, txt)
            class(plot), intent(inout) :: this
            character(len = *), intent(in) :: txt
        end subroutine
 
        pure module function plt_has_title(this) result(x)
            class(plot), intent(in) :: this
            logical :: x
        end function
 
        module function plt_get_legend(this) result(x)
            class(plot), intent(in) :: this
            type(legend), pointer :: x
        end function
 
        pure module function plt_get_count(this) result(x)
            class(plot), intent(in) :: this
            integer(int32) :: x
        end function
 
        module subroutine plt_push_data(this, x, err)
            class(plot), intent(inout) :: this
            class(plot_data), intent(inout) :: x
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module subroutine plt_pop_data(this)
            class(plot), intent(inout) :: this
        end subroutine
 
        module subroutine plt_clear_all(this)
            class(plot), intent(inout) :: this
        end subroutine
 
        module function plt_get(this, i) result(x)
            class(plot), intent(in) :: this
            integer(int32), intent(in) :: i
            class(plot_data), pointer :: x
        end function
 
        module subroutine plt_set(this, i, x)
            class(plot), intent(inout) :: this
            integer(int32), intent(in) :: i
            class(plot_data), intent(in) :: x
        end subroutine
 
        module function plt_get_term(this) result(x)
            class(plot), intent(in) :: this
            class(terminal), pointer :: x
        end function
 
        pure module function plt_get_show_grid(this) result(x)
            class(plot), intent(in) :: this
            logical :: x
        end function
 
        module subroutine plt_set_show_grid(this, x)
            class(plot), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module subroutine plt_draw(this, persist, err)
            class(plot), intent(in) :: this
            logical, intent(in), optional :: persist
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module subroutine plt_save(this, fname, err)
            class(plot), intent(in) :: this
            character(len = *), intent(in) :: fname
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module function plt_get_font(this) result(x)
            class(plot), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module subroutine plt_set_font(this, x)
            class(plot), intent(inout) :: this
            character(len = *), intent(in) :: x
        end subroutine
 
        module function plt_get_font_size(this) result(x)
            class(plot), intent(in) :: this
            integer(int32) :: x
        end function
 
        module subroutine plt_set_font_size(this, x)
            class(plot), intent(inout) :: this
            integer(int32), intent(in) :: x
        end subroutine
 
        pure module function plt_get_tics_in(this) result(x)
            class(plot), intent(in) :: this
            logical :: x
        end function
 
        module subroutine plt_set_tics_in(this, x)
            class(plot), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function plt_get_draw_border(this) result(x)
            class(plot), intent(in) :: this
            logical :: x
        end function
 
        module subroutine plt_set_draw_border(this, x)
            class(plot), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module subroutine plt_push_label(this, lbl, err)
            class(plot), intent(inout) :: this
            class(plot_label), intent(in) :: lbl
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
         module subroutine plt_pop_label(this)
            class(plot), intent(inout) :: this
        end subroutine
 
        module function plt_get_label(this, i) result(x)
            class(plot), intent(in) :: this
            integer(int32), intent(in) :: i
            class(plot_label), pointer :: x
        end function
 
        module subroutine plt_set_label(this, i, x)
            class(plot), intent(inout) :: this
            integer(int32), intent(in) :: i
            class(plot_label), intent(in) :: x
        end subroutine
 
        pure module function plt_get_label_count(this) result(x)
            class(plot), intent(in) :: this
            integer(int32) :: x
        end function
 
        module subroutine plt_clear_labels(this)
            class(plot), intent(inout) :: this
        end subroutine
 
        pure module function plt_get_axis_equal(this) result(rst)
            class(plot), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine plt_set_axis_equal(this, x)
            class(plot), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module function plt_get_colormap(this) result(x)
            class(plot), intent(in) :: this
            class(colormap), pointer :: x
        end function
 
        module subroutine plt_set_colormap(this, x, err)
            class(plot), intent(inout) :: this
            class(colormap), intent(in) :: x
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        pure module function plt_get_show_colorbar(this) result(x)
            class(plot), intent(in) :: this
            logical :: x
        end function
 
        module subroutine plt_set_show_colorbar(this, x)
            class(plot), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module function plt_get_cmd(this) result(x)
            class(plot), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module subroutine plt_push_arrow(this, x, err)
            class(plot), intent(inout) :: this
            class(plot_arrow), intent(in) :: x
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module subroutine plt_pop_arrow(this)
            class(plot), intent(inout) :: this
        end subroutine
 
        module function plt_get_arrow(this, i) result(rst)
            class(plot), intent(in) :: this
            integer(int32), intent(in) :: i
            class(plot_arrow), pointer :: rst
        end function
 
        module subroutine plt_set_arrow(this, i, x)
            class(plot), intent(inout) :: this
            integer(int32), intent(in) :: i
            class(plot_arrow), intent(in) :: x
        end subroutine
 
        pure module function plt_get_arrow_count(this) result(rst)
            class(plot), intent(in) :: this
            integer(int32) :: rst
        end function
 
        module subroutine plt_clear_arrows(this)
            class(plot), intent(inout) :: this
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_SCATTER_PLOT_DATA.F90
! ------------------------------------------------------------------------------
    type, abstract, extends(plot_data_colored) :: scatter_plot_data
    private
        logical :: m_drawline = .true.
        logical :: m_drawmarkers = .false.
        integer(int32) :: m_markerfrequency = 1
        real(real32) :: m_linewidth = 1.0
        integer(int32) :: m_linestyle = line_solid
        integer(int32) :: m_markertype = marker_x
        real(real32) :: m_markersize = 1.0
        logical :: m_simplifydata = .true.
        real(real64) :: m_simplifyfactor = 1.0d-3
        logical :: m_datadependentcolors = .false.
        logical :: m_filledcurve = .false.
        logical :: m_usevariablesizepoints = .false.
    contains
        procedure, public :: get_command_string => spd_get_cmd
        procedure, public :: get_line_width => spd_get_line_width
        procedure, public :: set_line_width => spd_set_line_width
        procedure, public :: get_line_style => spd_get_line_style
        procedure, public :: set_line_style => spd_set_line_style
        procedure, public :: get_draw_line => spd_get_draw_line
        procedure, public :: set_draw_line => spd_set_draw_line
        procedure, public :: get_draw_markers => spd_get_draw_markers
        procedure, public :: set_draw_markers => spd_set_draw_markers
        procedure, public :: get_marker_style => spd_get_marker_style
        procedure, public :: set_marker_style => spd_set_marker_style
        procedure, public :: get_marker_scaling => spd_get_marker_scaling
        procedure, public :: set_marker_scaling => spd_set_marker_scaling
        procedure, public :: get_marker_frequency => spd_get_marker_frequency
        procedure, public :: set_marker_frequency => spd_set_marker_frequency
        procedure(spd_get_int_value), deferred, public :: get_count
        procedure(spd_get_value), deferred, public :: get_x
        procedure(spd_set_value), deferred, public :: set_x
        procedure(spd_get_value), deferred, public :: get_y
        procedure(spd_set_value), deferred, public :: set_y
        procedure(spd_get_string_result), deferred, public :: get_axes_string
        procedure, public :: get_simplify_data => spd_get_simplify_data
        procedure, public :: set_simplify_data => spd_set_simplify_data
        procedure, public :: get_simplification_factor => spd_get_simplify_factor
        procedure, public :: set_simplification_factor => spd_set_simplify_factor
        procedure, public :: get_use_data_dependent_colors => &
            spd_get_data_dependent_colors
        procedure, public :: set_use_data_dependent_colors => &
            spd_set_data_dependent_colors
        procedure, public :: get_fill_curve => spd_get_filled
        procedure, public :: set_fill_curve => spd_set_filled
        procedure, public :: get_use_variable_size_points => spd_get_use_var_point_size
        procedure, public :: set_use_variable_size_points => spd_set_use_var_point_size
    end type
 
! ------------------------------------------------------------------------------
    interface
        module function spd_get_cmd(this) result(x)
            class(scatter_plot_data), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        pure module function spd_get_line_width(this) result(x)
            class(scatter_plot_data), intent(in) :: this
            real(real32) :: x
        end function
 
        module subroutine spd_set_line_width(this, x)
            class(scatter_plot_data), intent(inout) :: this
            real(real32), intent(in) :: x
        end subroutine
 
        pure module function spd_get_line_style(this) result(x)
            class(scatter_plot_data), intent(in) :: this
            integer(int32) :: x
        end function
 
        module subroutine spd_set_line_style(this, x)
            class(scatter_plot_data), intent(inout) :: this
            integer(int32), intent(in) :: x
        end subroutine
 
        pure module function spd_get_draw_line(this) result(x)
            class(scatter_plot_data), intent(in) :: this
            logical :: x
        end function
 
        module subroutine spd_set_draw_line(this, x)
            class(scatter_plot_data), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function spd_get_draw_markers(this) result(x)
            class(scatter_plot_data), intent(in) :: this
            logical :: x
        end function
 
        module subroutine spd_set_draw_markers(this, x)
            class(scatter_plot_data), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function spd_get_marker_style(this) result(x)
            class(scatter_plot_data), intent(in) :: this
            integer(int32) :: x
        end function
 
        module subroutine spd_set_marker_style(this, x)
            class(scatter_plot_data), intent(inout) :: this
            integer(int32), intent(in) :: x
        end subroutine
 
        pure module function spd_get_marker_scaling(this) result(x)
            class(scatter_plot_data), intent(in) :: this
            real(real32) :: x
        end function
 
        module subroutine spd_set_marker_scaling(this, x)
            class(scatter_plot_data), intent(inout) :: this
            real(real32), intent(in) :: x
        end subroutine
 
        pure module function spd_get_marker_frequency(this) result(x)
            class(scatter_plot_data), intent(in) :: this
            integer(int32) :: x
        end function
 
        module subroutine spd_set_marker_frequency(this, x)
            class(scatter_plot_data), intent(inout) :: this
            integer(int32), intent(in) :: x
        end subroutine
 
        pure module function spd_get_simplify_data(this) result(x)
            class(scatter_plot_data), intent(in) :: this
            logical :: x
        end function
        
        module subroutine spd_set_simplify_data(this, x)
            class(scatter_plot_data), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function spd_get_simplify_factor(this) result(x)
            class(scatter_plot_data), intent(in) :: this
            real(real64) :: x
        end function
        
        module subroutine spd_set_simplify_factor(this, x)
            class(scatter_plot_data), intent(inout) :: this
            real(real64), intent(in) :: x
        end subroutine
 
        pure module function spd_get_data_dependent_colors(this) result(rst)
            class(scatter_plot_data), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine spd_set_data_dependent_colors(this, x)
            class(scatter_plot_data), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function spd_get_filled(this) result(rst)
            class(scatter_plot_data), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine spd_set_filled(this, x)
            class(scatter_plot_data), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function spd_get_use_var_point_size(this) result(rst)
            class(scatter_plot_data), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine spd_set_use_var_point_size(this, x)
            class(scatter_plot_data), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_PLOT_DATA_2D.F90
! ------------------------------------------------------------------------------
    type, extends(scatter_plot_data) :: plot_data_2d
    private
        real(real64), allocatable, dimension(:,:) :: m_data
        logical :: m_usey2 = .false.
    contains
        procedure, public :: get_axes_string => pd2d_get_axes_cmd
        procedure, public :: get_data_string => pd2d_get_data_cmd
        procedure, public :: get_count => pd2d_get_data_count
        procedure, public :: get_x => pd2d_get_x_data
        procedure, public :: set_x => pd2d_set_x_data
        procedure, public :: get_y => pd2d_get_y_data
        procedure, public :: set_y => pd2d_set_y_data
        procedure, public :: get_draw_against_y2 => pd2d_get_draw_against_y2
        procedure, public :: set_draw_against_y2 => pd2d_set_draw_against_y2
        generic, public :: define_data => pd2d_set_data_1, pd2d_set_data_2
        procedure :: pd2d_set_data_1
        procedure :: pd2d_set_data_2
 
        procedure, public :: get_x_data => pd2d_get_x_array
        procedure, public :: get_y_data => pd2d_get_y_array
        procedure, public :: get_color_data => pd2d_get_c_array
        procedure, public :: get_point_size_data => pd2d_get_ps_array
    end type
 
! ------------------------------------------------------------------------------
    interface
        module function pd2d_get_axes_cmd(this) result(x)
            class(plot_data_2d), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function pd2d_get_data_cmd(this) result(x)
            class(plot_data_2d), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        pure module function pd2d_get_data_count(this) result(x)
            class(plot_data_2d), intent(in) :: this
            integer(int32) :: x
        end function
 
        pure module function pd2d_get_x_data(this, index) result(x)
            class(plot_data_2d), intent(in) :: this
            integer(int32), intent(in) :: index
            real(real64) :: x
        end function
 
        module subroutine pd2d_set_x_data(this, index, x)
            class(plot_data_2d), intent(inout) :: this
            integer(int32), intent(in) :: index
            real(real64), intent(in) :: x
        end subroutine
 
        pure module function pd2d_get_y_data(this, index) result(x)
            class(plot_data_2d), intent(in) :: this
            integer(int32), intent(in) :: index
            real(real64) :: x
        end function
 
        module subroutine pd2d_set_y_data(this, index, x)
            class(plot_data_2d), intent(inout) :: this
            integer(int32), intent(in) :: index
            real(real64), intent(in) :: x
        end subroutine
 
        module subroutine pd2d_set_data_1(this, x, y, c, ps, err)
            class(plot_data_2d), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: x, y
            real(real64), intent(in), dimension(:), optional :: c, ps
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        pure module function pd2d_get_draw_against_y2(this) result(x)
            class(plot_data_2d), intent(in) :: this
            logical :: x
        end function
 
        module subroutine pd2d_set_draw_against_y2(this, x)
            class(plot_data_2d), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module subroutine pd2d_set_data_2(this, y, err)
            class(plot_data_2d), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: y
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module function pd2d_get_x_array(this) result(x)
            class(plot_data_2d), intent(in) :: this
            real(real64), allocatable, dimension(:) :: x
        end function
 
        module function pd2d_get_y_array(this) result(x)
            class(plot_data_2d), intent(in) :: this
            real(real64), allocatable, dimension(:) :: x
        end function
 
        module function pd2d_get_c_array(this) result(x)
            class(plot_data_2d), intent(in) :: this
            real(real64), allocatable, dimension(:) :: x
        end function
 
        module function pd2d_get_ps_array(this) result(x)
            class(plot_data_2d), intent(in) :: this
            real(real64), allocatable, dimension(:) :: x
        end function
    end interface
 
! ******************************************************************************
! FPLOT_PLOT_DATA_3D.F90
! ------------------------------------------------------------------------------
    type, extends(scatter_plot_data) :: plot_data_3d
    private
        real(real64), allocatable, dimension(:,:) :: m_data
    contains
        procedure, public :: get_count => pd3d_get_data_count
        procedure, public :: get_x => pd3d_get_x_data
        procedure, public :: set_x => pd3d_set_x_data
        procedure, public :: get_y => pd3d_get_y_data
        procedure, public :: set_y => pd3d_set_y_data
        procedure, public :: get_z => pd3d_get_z_data
        procedure, public :: set_z => pd3d_set_z_data
        procedure, public :: get_axes_string => pd3d_get_axes_cmd
        procedure, public :: get_data_string => pd3d_get_data_cmd
        procedure, public :: define_data => pd3d_set_data_1
        procedure, public :: get_x_data => pd3d_get_x_array
        procedure, public :: get_y_data => pd3d_get_y_array
        procedure, public :: get_z_data => pd3d_get_z_array
        procedure, public :: get_color_data => pd3d_get_c_array
        procedure, public :: get_point_size_data => pd3d_get_c_array
    end type
 
! ------------------------------------------------------------------------------
    interface
        pure module function pd3d_get_data_count(this) result(x)
            class(plot_data_3d), intent(in) :: this
            integer(int32) :: x
        end function
 
        pure module function pd3d_get_x_data(this, index) result(x)
            class(plot_data_3d), intent(in) :: this
            integer(int32), intent(in) :: index
            real(real64) :: x
        end function
 
        module subroutine pd3d_set_x_data(this, index, x)
            class(plot_data_3d), intent(inout) :: this
            integer(int32), intent(in) :: index
            real(real64), intent(in) :: x
        end subroutine
 
        pure module function pd3d_get_y_data(this, index) result(x)
            class(plot_data_3d), intent(in) :: this
            integer(int32), intent(in) :: index
            real(real64) :: x
        end function
 
        module subroutine pd3d_set_y_data(this, index, x)
            class(plot_data_3d), intent(inout) :: this
            integer(int32), intent(in) :: index
            real(real64), intent(in) :: x
        end subroutine
 
        pure module function pd3d_get_z_data(this, index) result(x)
            class(plot_data_3d), intent(in) :: this
            integer(int32), intent(in) :: index
            real(real64) :: x
        end function
 
        module subroutine pd3d_set_z_data(this, index, x)
            class(plot_data_3d), intent(inout) :: this
            integer(int32), intent(in) :: index
            real(real64), intent(in) :: x
        end subroutine
 
        module function pd3d_get_axes_cmd(this) result(x)
            class(plot_data_3d), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function pd3d_get_data_cmd(this) result(x)
            class(plot_data_3d), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module subroutine pd3d_set_data_1(this, x, y, z, c, ps, err)
            class(plot_data_3d), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: x, y, z
            real(real64), intent(in), dimension(:), optional :: c, ps
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module function pd3d_get_x_array(this) result(x)
            class(plot_data_3d), intent(in) :: this
            real(real64), allocatable, dimension(:) :: x
        end function
 
        module function pd3d_get_y_array(this) result(x)
            class(plot_data_3d), intent(in) :: this
            real(real64), allocatable, dimension(:) :: x
        end function
 
        module function pd3d_get_z_array(this) result(x)
            class(plot_data_3d), intent(in) :: this
            real(real64), allocatable, dimension(:) :: x
        end function
 
        module function pd3d_get_c_array(this) result(x)
            class(plot_data_3d), intent(in) :: this
            real(real64), allocatable, dimension(:) :: x
        end function
 
        module function pd3d_get_ps_array(this) result(x)
            class(plot_data_3d), intent(in) :: this
            real(real64), allocatable, dimension(:) :: x
        end function
    end interface
 
! ******************************************************************************
! FPLOT_SURFACE_PLOT_DATA.F90
! ------------------------------------------------------------------------------
    type, extends(plot_data) :: surface_plot_data
    private
        real(real64), allocatable, dimension(:,:) :: m_x
        real(real64), allocatable, dimension(:,:) :: m_y
        real(real64), allocatable, dimension(:,:) :: m_z
        logical :: m_wireframe = .false.
    contains
        procedure, public :: get_size => surfd_get_size
        procedure, public :: get_x => surfd_get_x
        procedure, public :: set_x => surfd_set_x
        procedure, public :: get_y => surfd_get_y
        procedure, public :: set_y => surfd_set_y
        procedure, public :: get_z => surfd_get_z
        procedure, public :: set_z => surfd_set_z
        procedure, public :: get_use_wireframe => surfd_get_wireframe
        procedure, public :: set_use_wireframe => surfd_set_wireframe
        procedure, public :: get_command_string => surfd_get_cmd
        procedure, public :: get_data_string => surfd_get_data_cmd
        procedure, public :: define_data => surfd_set_data_1
    end type
 
! ------------------------------------------------------------------------------
    interface
        pure module function surfd_get_size(this, dim) result(x)
            class(surface_plot_data), intent(in) :: this
            integer(int32), intent(in) :: dim
            integer(int32) :: x
        end function
 
        pure module function surfd_get_x(this, i, j) result(x)
            class(surface_plot_data), intent(in) :: this
            integer(int32), intent(in) :: i, j
            real(real64) :: x
        end function
 
        module subroutine surfd_set_x(this, i, j, x)
            class(surface_plot_data), intent(inout) :: this
            integer(int32), intent(in) :: i, j
            real(real64), intent(in) :: x
        end subroutine
 
        pure module function surfd_get_y(this, i, j) result(x)
            class(surface_plot_data), intent(in) :: this
            integer(int32), intent(in) :: i, j
            real(real64) :: x
        end function
 
        module subroutine surfd_set_y(this, i, j, x)
            class(surface_plot_data), intent(inout) :: this
            integer(int32), intent(in) :: i, j
            real(real64), intent(in) :: x
        end subroutine
 
        pure module function surfd_get_z(this, i, j) result(x)
            class(surface_plot_data), intent(in) :: this
            integer(int32), intent(in) :: i, j
            real(real64) :: x
        end function
 
        module subroutine surfd_set_z(this, i, j, x)
            class(surface_plot_data), intent(inout) :: this
            integer(int32), intent(in) :: i, j
            real(real64), intent(in) :: x
        end subroutine
 
        pure module function surfd_get_wireframe(this) result(x)
            class(surface_plot_data), intent(in) :: this
            logical :: x
        end function
 
        module subroutine surfd_set_wireframe(this, x)
            class(surface_plot_data), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module function surfd_get_cmd(this) result(x)
            class(surface_plot_data), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function surfd_get_data_cmd(this) result(x)
            class(surface_plot_data), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module subroutine surfd_set_data_1(this, x, y, z, err)
            class(surface_plot_data), intent(inout) :: this
            real(real64), intent(in), dimension(:,:) :: x, y, z
            class(errors), intent(inout), optional, target :: err
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_PLOT_2D.F90
! ------------------------------------------------------------------------------
    type, extends(plot) :: plot_2d
    private
        type(x_axis), pointer :: m_xaxis => null()
        type(y_axis), pointer :: m_yaxis => null()
        type(y2_axis), pointer :: m_y2axis => null()
        logical :: m_usey2 = .false.
        logical :: m_set2square = .false.
    contains
        final :: p2d_clean_up
        procedure, public :: initialize => p2d_init
        procedure, public :: get_command_string => p2d_get_cmd
        procedure, public :: get_x_axis => p2d_get_x_axis
        procedure, public :: get_y_axis => p2d_get_y_axis
        procedure, public :: get_y2_axis => p2d_get_y2_axis
        procedure, public :: get_use_y2_axis => p2d_get_use_y2
        procedure, public :: set_use_y2_axis => p2d_set_use_y2
        procedure, public :: get_square_axes => p2d_get_square_axes
        procedure, public :: set_square_axes => p2d_set_square_axes
    end type
 
! ------------------------------------------------------------------------------
    interface
        module subroutine p2d_clean_up(this)
            type(plot_2d), intent(inout) :: this
        end subroutine
 
        module subroutine p2d_init(this, term, fname, err)
            class(plot_2d), intent(inout) :: this
            integer(int32), intent(in), optional :: term
            character(len = *), intent(in), optional :: fname
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module function p2d_get_cmd(this) result(x)
            class(plot_2d), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function p2d_get_x_axis(this) result(ptr)
            class(plot_2d), intent(in) :: this
            class(plot_axis), pointer :: ptr
        end function
 
        module function p2d_get_y_axis(this) result(ptr)
            class(plot_2d), intent(in) :: this
            class(plot_axis), pointer :: ptr
        end function
 
        module function p2d_get_y2_axis(this) result(ptr)
            class(plot_2d), intent(in) :: this
            class(plot_axis), pointer :: ptr
        end function
 
        pure module function p2d_get_use_y2(this) result(x)
            class(plot_2d), intent(in) :: this
            logical :: x
        end function
 
        module subroutine p2d_set_use_y2(this, x)
            class(plot_2d), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function p2d_get_square_axes(this) result(rst)
            class(plot_2d), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine p2d_set_square_axes(this, x)
            class(plot_2d), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_PLOT_3D.F90
! ------------------------------------------------------------------------------
    type, extends(plot) :: plot_3d
    private
        type(x_axis), pointer :: m_xaxis => null()
        type(y_axis), pointer :: m_yaxis => null()
        type(z_axis), pointer :: m_zaxis => null()
        real(real64) :: m_elevation = 60.0d0
        real(real64) :: m_azimuth = 30.0d0
        logical :: m_zintersect = .true.
        logical :: m_setmap = .false.
        integer(int32) :: m_csys = coordinates_cartesian
    contains
        final :: p3d_clean_up
        procedure, public :: initialize => p3d_init
        procedure, public :: get_command_string => p3d_get_cmd
        procedure, public :: get_x_axis => p3d_get_x_axis
        procedure, public :: get_y_axis => p3d_get_y_axis
        procedure, public :: get_z_axis => p3d_get_z_axis
        procedure, public :: get_elevation => p3d_get_elevation
        procedure, public :: set_elevation => p3d_set_elevation
        procedure, public :: get_azimuth => p3d_get_azimuth
        procedure, public :: set_azimuth => p3d_set_azimuth
        procedure, public :: get_z_intersect_xy => p3d_get_z_axis_intersect
        procedure, public :: set_z_intersect_xy => p3d_set_z_axis_intersect
        procedure, public :: get_use_map_view => p3d_get_use_map_view
        procedure, public :: set_use_map_view => p3d_set_use_map_view
        procedure, public :: get_coordinate_system => p3d_get_csys
        procedure, public :: set_coordinate_system => p3d_set_csys
    end type
 
! ------------------------------------------------------------------------------
    interface
        module subroutine p3d_clean_up(this)
            type(plot_3d), intent(inout) :: this
        end subroutine
 
        module subroutine p3d_init(this, term, fname, err)
            class(plot_3d), intent(inout) :: this
            integer(int32), intent(in), optional :: term
            character(len = *), intent(in), optional :: fname
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module function p3d_get_cmd(this) result(x)
            class(plot_3d), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function p3d_get_x_axis(this) result(ptr)
            class(plot_3d), intent(in) :: this
            class(plot_axis), pointer :: ptr
        end function
 
        module function p3d_get_y_axis(this) result(ptr)
            class(plot_3d), intent(in) :: this
            class(plot_axis), pointer :: ptr
        end function
 
        module function p3d_get_z_axis(this) result(ptr)
            class(plot_3d), intent(in) :: this
            class(plot_axis), pointer :: ptr
        end function
 
        pure module function p3d_get_elevation(this) result(x)
            class(plot_3d), intent(in) :: this
            real(real64) :: x
        end function
 
        module subroutine p3d_set_elevation(this, x)
            class(plot_3d), intent(inout) :: this
            real(real64), intent(in) :: x
        end subroutine
 
        pure module function p3d_get_azimuth(this) result(x)
            class(plot_3d), intent(in) :: this
            real(real64) :: x
        end function
 
        module subroutine p3d_set_azimuth(this, x)
            class(plot_3d), intent(inout) :: this
            real(real64), intent(in) :: x
        end subroutine
 
        pure module function p3d_get_z_axis_intersect(this) result(x)
            class(plot_3d), intent(in) :: this
            logical :: x
        end function
 
        module subroutine p3d_set_z_axis_intersect(this, x)
            class(plot_3d), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function p3d_get_use_map_view(this) result(rst)
            class(plot_3d), intent(in) :: this
            logical :: rst
        end function
        
        module subroutine p3d_set_use_map_view(this, x)
            class(plot_3d), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function p3d_get_csys(this) result(rst)
            class(plot_3d), intent(in) :: this
            integer(int32) :: rst
        end function
 
        module subroutine p3d_set_csys(this, x)
            class(plot_3d), intent(inout) :: this
            integer(int32), intent(in) :: x
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_SURFACE_PLOT.F90
! ------------------------------------------------------------------------------
    type, extends(plot_3d) :: surface_plot
    private
        logical :: m_showhidden = .false.
        ! class(colormap), pointer :: m_colormap
        logical :: m_smooth = .true.
        logical :: m_contour = .false.
        ! !> Show the colorbar?
        ! logical :: m_showColorbar = .true.
        logical :: m_uselighting = .false.
        real(real32) :: m_lightintensity = 0.5
        real(real32) :: m_specular = 0.5
        real(real32) :: m_transparency = 1.0
    contains
        ! final :: surf_clean_up
        procedure, public :: initialize => surf_init
        procedure, public :: get_show_hidden => surf_get_show_hidden
        procedure, public :: set_show_hidden => surf_set_show_hidden
        procedure, public :: get_command_string => surf_get_cmd
        procedure, public :: get_allow_smoothing => surf_get_smooth
        procedure, public :: set_allow_smoothing => surf_set_smooth
        procedure, public :: get_show_contours => surf_get_show_contours
        procedure, public :: set_show_contours => surf_set_show_contours
        procedure, public :: get_use_lighting => surf_get_use_lighting
        procedure, public :: set_use_lighting => surf_set_use_lighting
        procedure, public :: get_light_intensity => surf_get_light_intensity
        procedure, public :: set_light_intensity => surf_set_light_intensity
        procedure, public :: get_specular_intensity => surf_get_specular_intensity
        procedure, public :: set_specular_intensity => surf_set_specular_intensity
        procedure, public :: get_transparency => surf_get_transparency
        procedure, public :: set_transparency => surf_set_transparency
    end type
 
! ------------------------------------------------------------------------------
    interface
        ! module subroutine surf_clean_up(this)
        !     type(surface_plot), intent(inout) :: this
        ! end subroutine
 
        module subroutine surf_init(this, term, fname, err)
            class(surface_plot), intent(inout) :: this
            integer(int32), intent(in), optional :: term
            character(len = *), intent(in), optional :: fname
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        pure module function surf_get_show_hidden(this) result(x)
            class(surface_plot), intent(in) :: this
            logical :: x
        end function
 
        module subroutine surf_set_show_hidden(this, x)
            class(surface_plot), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module function surf_get_cmd(this) result(x)
            class(surface_plot), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        ! module function surf_get_colormap(this) result(x)
        !     class(surface_plot), intent(in) :: this
        !     class(colormap), pointer :: x
        ! end function
 
        ! module subroutine surf_set_colormap(this, x, err)
        !     class(surface_plot), intent(inout) :: this
        !     class(colormap), intent(in) :: x
        !     class(errors), intent(inout), optional, target :: err
        ! end subroutine
 
        pure module function surf_get_smooth(this) result(x)
            class(surface_plot), intent(in) :: this
            logical :: x
        end function
 
        module subroutine surf_set_smooth(this, x)
            class(surface_plot), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function surf_get_show_contours(this) result(x)
            class(surface_plot), intent(in) :: this
            logical :: x
        end function
 
        module subroutine surf_set_show_contours(this, x)
            class(surface_plot), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        ! pure module function surf_get_show_colorbar(this) result(x)
        !     class(surface_plot), intent(in) :: this
        !     logical :: x
        ! end function
 
        ! module subroutine surf_set_show_colorbar(this, x)
        !     class(surface_plot), intent(inout) :: this
        !     logical, intent(in) :: x
        ! end subroutine
 
        pure module function surf_get_use_lighting(this) result(x)
            class(surface_plot), intent(in) :: this
            logical :: x
        end function
 
        module subroutine surf_set_use_lighting(this, x)
            class(surface_plot), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function surf_get_light_intensity(this) result(x)
            class(surface_plot), intent(in) :: this
            real(real32) :: x
        end function
 
        module subroutine surf_set_light_intensity(this, x)
            class(surface_plot), intent(inout) :: this
            real(real32), intent(in) :: x
        end subroutine
 
        pure module function surf_get_specular_intensity(this) result(x)
            class(surface_plot), intent(in) :: this
            real(real32) :: x
        end function
 
        module subroutine surf_set_specular_intensity(this, x)
            class(surface_plot), intent(inout) :: this
            real(real32), intent(in) :: x
        end subroutine
 
        pure module function surf_get_transparency(this) result(x)
            class(surface_plot), intent(in) :: this
            real(real32) :: x
        end function
 
        module subroutine surf_set_transparency(this, x)
            class(surface_plot), intent(inout) :: this
            real(real32), intent(in) :: x
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_AXIS.F90
! ------------------------------------------------------------------------------
    type, extends(plot_axis) :: x_axis
        character :: m_id = "x"
    contains
        procedure, public :: get_id_string => xa_get_id
    end type
 
! ------------------------------------------------------------------------------
    type, extends(plot_axis) :: y_axis
        character :: m_id = "y"
    contains
        procedure, public :: get_id_string => ya_get_id
    end type
 
! ------------------------------------------------------------------------------
    type, extends(plot_axis) :: y2_axis
        character(len = 2) :: m_id = "y2"
    contains
        procedure, public :: get_id_string => y2a_get_id
    end type
 
! ------------------------------------------------------------------------------
    type, extends(plot_axis) :: z_axis
        character :: m_id = "z"
    contains
        procedure, public :: get_id_string => za_get_id
    end type
 
! ------------------------------------------------------------------------------
    interface
        module function xa_get_id(this) result(x)
            class(x_axis), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function ya_get_id(this) result(x)
            class(y_axis), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function y2a_get_id(this) result(x)
            class(y2_axis), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function za_get_id(this) result(x)
            class(z_axis), intent(in) :: this
            character(len = :), allocatable :: x
        end function
    end interface
 
! ******************************************************************************
! ABSTRACT METHOD INTERFACES
! ------------------------------------------------------------------------------
    interface
 
        function get_string_result(this) result(x)
            import plot_object
            class(plot_object), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        function term_get_string_result(this) result(x)
            import terminal
            class(terminal), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        function pd_get_string_result(this) result(x)
            import plot_data
            class(plot_data), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        function pa_get_string_result(this) result(x)
            import plot_axis
            class(plot_axis), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        pure function spd_get_value(this, index) result(x)
            use, intrinsic :: iso_fortran_env, only : int32, real64
            import scatter_plot_data
            class(scatter_plot_data), intent(in) :: this
            integer(int32), intent(in) :: index
            real(real64) :: x
        end function
 
        subroutine spd_set_value(this, index, x)
            use, intrinsic :: iso_fortran_env, only : int32, real64
            import scatter_plot_data
            class(scatter_plot_data), intent(inout) :: this
            integer(int32), intent(in) :: index
            real(real64), intent(in) :: x
        end subroutine
 
        pure function spd_get_int_value(this) result(x)
            use, intrinsic :: iso_fortran_env, only : int32
            import scatter_plot_data
            class(scatter_plot_data), intent(in) :: this
            integer(int32) :: x
        end function
 
        function spd_get_string_result(this) result(x)
            import scatter_plot_data
            class(scatter_plot_data), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        function cm_get_string_result(this) result(x)
            import colormap
            class(colormap), intent(in) :: this
            character(len = :), allocatable :: x
        end function
    end interface
 
! ******************************************************************************
! FPLOT_MULTIPLOT.F90
! ------------------------------------------------------------------------------
    type, extends(plot_object) :: multiplot
        type(list) :: m_plots
        integer(int32) :: m_rows = 0
        integer(int32) :: m_cols = 0
        character(len = PLOTDATA_MAX_NAME_LENGTH) :: m_title
        logical :: m_hastitle = .false.
        class(terminal), pointer :: m_terminal => null()
    contains
        final :: mp_clean
        procedure, public :: get_command_string => mp_get_command
        procedure, public :: initialize => mp_init
        procedure, public :: get_row_count => mp_get_rows
        procedure, public :: get_column_count => mp_get_cols
        procedure, public :: get_plot_count => mp_get_count
        procedure, public :: get_title => mp_get_title
        procedure, public :: set_title => mp_set_title
        procedure, public :: draw => mp_draw
        procedure, public :: get => mp_get
        procedure, public :: set => mp_set
        procedure, public :: is_title_defined => mp_has_title
        procedure, public :: get_terminal => mp_get_term
        procedure, public :: save_file => mp_save
        procedure, public :: get_font_name => mp_get_font
        procedure, public :: set_font_name => mp_set_font
        procedure, public :: get_font_size => mp_get_font_size
        procedure, public :: set_font_size => mp_set_font_size
    end type
 
! ------------------------------------------------------------------------------
    interface
        module function mp_get_command(this) result(x)
            class(multiplot), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module subroutine mp_init(this, m, n, term, err)
            class(multiplot), intent(inout) :: this
            integer(int32), intent(in) :: m, n
            integer(int32), intent(in), optional :: term
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module subroutine mp_clean(this)
            type(multiplot), intent(inout) :: this
        end subroutine
 
        pure module function mp_get_rows(this) result(x)
            class(multiplot), intent(in) :: this
            integer(int32) :: x
        end function
 
        pure module function mp_get_cols(this) result(x)
            class(multiplot), intent(in) :: this
            integer(int32) :: x
        end function
 
        pure module function mp_get_count(this) result(x)
            class(multiplot), intent(in) :: this
            integer(int32) :: x
        end function
 
        module function mp_get_title(this) result(x)
            class(multiplot), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module subroutine mp_set_title(this, x)
            class(multiplot), intent(inout) :: this
            character(len = *), intent(in) :: x
        end subroutine
 
        module subroutine mp_draw(this, persist, err)
            class(multiplot), intent(in) :: this
            logical, intent(in), optional :: persist
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module function mp_get(this, i, j) result(x)
            class(multiplot), intent(in) :: this
            integer(int32), intent(in) :: i, j
            class(plot), pointer :: x
        end function
 
        module subroutine mp_set(this, i, j, x)
            class(multiplot), intent(inout) :: this
            integer(int32), intent(in) :: i, j
            class(plot), intent(in) :: x
        end subroutine
 
        pure module function mp_has_title(this) result(x)
            class(multiplot), intent(in) :: this
            logical :: x
        end function
 
        module function mp_get_term(this) result(x)
            class(multiplot), intent(in) :: this
            class(terminal), pointer :: x
        end function
 
        module subroutine mp_save(this, fname, err)
            class(multiplot), intent(in) :: this
            character(len = *), intent(in) :: fname
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module function mp_get_font(this) result(x)
            class(multiplot), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module subroutine mp_set_font(this, x)
            class(multiplot), intent(inout) :: this
            character(len = *), intent(in) :: x
        end subroutine
 
        module function mp_get_font_size(this) result(x)
            class(multiplot), intent(in) :: this
            integer(int32) :: x
        end function
 
        module subroutine mp_set_font_size(this, x)
            class(multiplot), intent(inout) :: this
            integer(int32), intent(in) :: x
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_PLOT_DATA_ERRORS.F90
! ------------------------------------------------------------------------------
    type, extends(plot_data_colored) :: plot_data_error_bars
        logical :: m_xbars = .false.
        logical :: m_ybars = .false.
        real(real64), allocatable, dimension(:,:) :: m_data
        logical :: m_box = .false.
        logical :: m_range = .false.
    contains
        procedure, public :: get_command_string => pde_get_cmd
        procedure, public :: get_data_string => pde_get_data_cmd
        generic, public :: define_x_error_data => pde_define_x_err, &
            pde_define_x_err_lim
        generic, public :: define_y_error_data => pde_define_y_err, &
            pde_define_y_err_lim
        generic, public :: define_xy_error_data => pde_define_xy_err, &
            pde_define_xy_err_lim
        procedure, public :: get_plot_x_error_bars => pde_get_plot_x_err
        procedure, public :: get_plot_y_error_bars => pde_get_plot_y_err
        procedure, public :: get_count => pde_get_count
        procedure, public :: get_use_error_box => pde_get_box
        procedure, public :: set_use_error_box => pde_set_box
        procedure, public :: get_use_range => pde_get_use_range
 
        procedure :: pde_define_x_err
        procedure :: pde_define_y_err
        procedure :: pde_define_xy_err
        procedure :: pde_define_x_err_lim
        procedure :: pde_define_y_err_lim
        procedure :: pde_define_xy_err_lim
    end type
 
! ------------------------------------------------------------------------------
    interface
        module function pde_get_cmd(this) result(cmd)
            class(plot_data_error_bars), intent(in) :: this
            character(len = :), allocatable :: cmd
        end function
 
        module function pde_get_data_cmd(this) result(cmd)
            class(plot_data_error_bars), intent(in) :: this
            character(len = :), allocatable :: cmd
        end function
 
        module subroutine pde_define_x_err(this, x, y, xerr, err)
            class(plot_data_error_bars), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: x, y, xerr
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module subroutine pde_define_y_err(this, x, y, yerr, err)
            class(plot_data_error_bars), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: x, y, yerr
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module subroutine pde_define_xy_err(this, x, y, xerr, yerr, err)
            class(plot_data_error_bars), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: x, y, xerr, yerr
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        pure module function pde_get_plot_x_err(this) result(x)
            class(plot_data_error_bars), intent(in) :: this
            logical :: x
        end function
 
        pure module function pde_get_plot_y_err(this) result(x)
            class(plot_data_error_bars), intent(in) :: this
            logical :: x
        end function
 
        pure module function pde_get_count(this) result(x)
            class(plot_data_error_bars), intent(in) :: this
            integer(int32) :: x
        end function
 
        pure module function pde_get_box(this) result(x)
            class(plot_data_error_bars), intent(in) :: this
            logical :: x
        end function
 
        module subroutine pde_set_box(this, x)
            class(plot_data_error_bars), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function pde_get_use_range(this) result(x)
            class(plot_data_error_bars), intent(in) :: this
            logical :: x
        end function
 
        module subroutine pde_define_x_err_lim(this, x, y, xmin, xmax, err)
            class(plot_data_error_bars), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: x, y, xmin, xmax
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module subroutine pde_define_y_err_lim(this, x, y, ymin, ymax, err)
            class(plot_data_error_bars), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: x, y, ymin, ymax
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module subroutine pde_define_xy_err_lim(this, x, y, xmin, xmax, ymin, &
                ymax, err)
            class(plot_data_error_bars), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: x, y, xmin, xmax, &
                ymin, ymax
            class(errors), intent(inout), optional, target :: err
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_PLOT_DATA_BAR.F90
! ------------------------------------------------------------------------------
    type, extends(plot_data_colored) :: plot_data_bar
    private
        type(string), allocatable, dimension(:) :: m_axislabels
        real(real64), allocatable, dimension(:,:) :: m_bardata
        logical :: m_useaxislabels = .true.
        logical :: m_usey2 = .false.
        logical :: m_filled = .true.
        real(real32) :: m_alpha = 1.0
    contains
        procedure, public :: get_count => pdb_get_count
        procedure, public :: get => pdb_get_data
        procedure, public :: set => pdb_set_data
        procedure, public :: get_data => pdb_get_data_set
        procedure, public :: get_label => pdb_get_label
        procedure, public :: set_label => pdb_set_label
        procedure, public :: get_use_labels => pdb_get_use_labels
        procedure, public :: set_use_labels => pdb_set_use_labels
        procedure, public :: get_command_string => pdb_get_cmd
        procedure, public :: get_data_string => pdb_get_data_cmd
        procedure, public :: get_axes_string => pdb_get_axes_cmd
        procedure, public :: get_bar_per_label_count => pdb_get_col_count
        procedure, public :: get_draw_against_y2 => pdb_get_use_y2
        procedure, public :: set_draw_against_y2 => pdb_set_use_y2
        procedure, public :: get_is_filled => pdb_get_is_filled
        procedure, public :: set_is_filled => pdb_set_is_filled
        procedure, public :: get_transparency => pdb_get_alpha
        procedure, public :: set_transparency => pdb_set_alpha
        generic, public :: define_data => pdb_set_data_1, pdb_set_data_2, &
            pdb_set_data_3
        procedure :: pdb_set_data_1
        procedure :: pdb_set_data_2
        procedure :: pdb_set_data_3
        procedure :: set_data_1 => pdb_set_data_1_core
        procedure :: set_data_2 => pdb_set_data_2_core
        procedure :: set_data_3 => pdb_set_data_3_core
    end type
 
! ------------------------------------------------------------------------------
    interface
        pure module function pdb_get_count(this) result(x)
            class(plot_data_bar), intent(in) :: this
            integer(int32) :: x
        end function
 
        pure module function pdb_get_data(this, index, col) result(x)
            class(plot_data_bar), intent(in) :: this
            integer(int32), intent(in) :: index, col
            real(real64) :: x
        end function
 
        module subroutine pdb_set_data(this, index, col, x)
            class(plot_data_bar), intent(inout) :: this
            integer(int32), intent(in) :: index, col
            real(real64), intent(in) :: x
        end subroutine
 
        pure module function pdb_get_data_set(this, col) result(x)
            class(plot_data_bar), intent(in) :: this
            integer(int32), intent(in) :: col
            real(real64), allocatable, dimension(:) :: x
        end function
 
        pure module function pdb_get_label(this, index) result(x)
            class(plot_data_bar), intent(in) :: this
            integer(int32), intent(in) :: index
            character(len = :), allocatable :: x
        end function
 
        module subroutine pdb_set_label(this, index, txt)
            class(plot_data_bar), intent(inout) :: this
            integer(int32) :: index
            character(len = *), intent(in) :: txt
        end subroutine
 
        pure module function pdb_get_use_labels(this) result(x)
            class(plot_data_bar), intent(in) :: this
            logical :: x
        end function
 
        module subroutine pdb_set_use_labels(this, x)
            class(plot_data_bar), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module function pdb_get_cmd(this) result(x)
            class(plot_data_bar), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function pdb_get_data_cmd(this) result(x)
            class(plot_data_bar), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function pdb_get_axes_cmd(this) result(x)
            class(plot_data_bar), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        pure module function pdb_get_col_count(this) result(x)
            class(plot_data_bar), intent(in) :: this
            integer(int32) :: x
        end function
 
        pure module function pdb_get_use_y2(this) result(x)
            class(plot_data_bar), intent(in) :: this
            logical :: x
        end function
 
        module subroutine pdb_set_use_y2(this, x)
            class(plot_data_bar), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function pdb_get_is_filled(this) result(x)
            class(plot_data_bar), intent(in) :: this
            logical :: x
        end function
 
        module subroutine pdb_set_is_filled(this, x)
            class(plot_data_bar), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module subroutine pdb_set_data_1(this, x, err)
            class(plot_data_bar), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: x
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module subroutine pdb_set_data_2(this, labels, x, err)
            class(plot_data_bar), intent(inout) :: this
            class(string), intent(in), dimension(:) :: labels
            real(real64), intent(in), dimension(:) :: x
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module subroutine pdb_set_data_3(this, labels, x, fmt, err)
            class(plot_data_bar), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: labels
            real(real64), intent(in), dimension(:) :: x
            character(len = *), intent(in), optional :: fmt
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        pure module function pdb_get_alpha(this) result(x)
            class(plot_data_bar), intent(in) :: this
            real(real32) :: x
        end function
 
        module subroutine pdb_set_alpha(this, x)
            class(plot_data_bar), intent(inout) :: this
            real(real32), intent(in) :: x
        end subroutine
 
        module subroutine pdb_set_data_1_core(this, x, err)
            class(plot_data_bar), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: x
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module subroutine pdb_set_data_2_core(this, labels, x, err)
            class(plot_data_bar), intent(inout) :: this
            class(string), intent(in), dimension(:) :: labels
            real(real64), intent(in), dimension(:) :: x
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module subroutine pdb_set_data_3_core(this, labels, x, fmt, err)
            class(plot_data_bar), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: labels
            real(real64), intent(in), dimension(:) :: x
            character(len = *), intent(in), optional :: fmt
            class(errors), intent(inout), optional, target :: err
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_PLOT_DATA_HISTOGRAM.F90
! ------------------------------------------------------------------------------
    type, extends(plot_data_bar) :: plot_data_histogram
    private
        integer(int32) :: m_bincount = 10
        character(len = :), allocatable :: m_numberfmt
    contains
        procedure, public :: get_bin_count => pdh_get_bin_count
        procedure, public :: set_bin_count => pdh_set_bin_count
        procedure, public :: bin_data => pdh_bin_data
        procedure, public :: get_extreme_values => pdh_get_extremes
        procedure, public :: get_number_format => pdh_get_num_fmt
        procedure, public :: set_number_format => pdh_set_num_fmt
        procedure :: set_data_1 => pdh_set_data_1
        procedure :: set_data_2 => pdh_set_data_2
        procedure :: set_data_3 => pdh_set_data_3
    end type
 
! ------------------------------------------------------------------------------
    interface
        pure module function pdh_get_bin_count(this) result(x)
            class(plot_data_histogram), intent(in) :: this
            integer(int32) :: x
        end function
 
        module subroutine pdh_set_bin_count(this, x)
            class(plot_data_histogram), intent(inout) :: this
            integer(int32), intent(in) :: x
        end subroutine
 
        module function pdh_bin_data(this, x, err) result(bx)
            class(plot_data_histogram), intent(in) :: this
            real(real64), intent(in), dimension(:) :: x
            class(errors), intent(inout), optional, target :: err
            real(real64), allocatable, dimension(:,:) :: bx
        end function
 
        pure module function pdh_get_extremes(this) result(x)
            class(plot_data_histogram), intent(in) :: this
            real(real64), dimension(2) :: x
        end function
 
        module subroutine pdh_set_data_1(this, x, err)
            class(plot_data_histogram), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: x
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module subroutine pdh_set_data_2(this, labels, x, err)
            class(plot_data_histogram), intent(inout) :: this
            class(string), intent(in), dimension(:) :: labels
            real(real64), intent(in), dimension(:) :: x
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module subroutine pdh_set_data_3(this, labels, x, fmt, err)
            class(plot_data_histogram), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: labels
            real(real64), intent(in), dimension(:) :: x
            character(len = *), intent(in), optional :: fmt
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        pure module function pdh_get_num_fmt(this) result(x)
            class(plot_data_histogram), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module subroutine pdh_set_num_fmt(this, x)
            class(plot_data_histogram), intent(inout) :: this
            character(len = *), intent(in) :: x
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_PLOT_BAR.F90
! ------------------------------------------------------------------------------
    type, extends(plot_2d) :: plot_bar
    private
        real(real32) :: m_barwidth = 0.75d0
    contains
        procedure, public :: get_bar_width => pb_get_bar_width
        procedure, public :: set_bar_width => pb_set_bar_width
        procedure, public :: get_command_string => pb_get_cmd
    end type
 
! ------------------------------------------------------------------------------
    interface
        pure module function pb_get_bar_width(this) result(x)
            class(plot_bar), intent(in) :: this
            real(real32) :: x
        end function
 
        module subroutine pb_set_bar_width(this, x)
            class(plot_bar), intent(inout) :: this
            real(real32), intent(in) :: x
        end subroutine
 
        module function pb_get_cmd(this) result(x)
            class(plot_bar), intent(in) :: this
            character(len = :), allocatable :: x
        end function
    end interface
 
 
! ******************************************************************************
! FPLOT_TRIANGULATIONS_DELAUNAY_2D.F90
! ------------------------------------------------------------------------------
    type delaunay_tri_2d
    private
        real(real64), allocatable, dimension(:) :: m_x
        real(real64), allocatable, dimension(:) :: m_y
        integer(int32), allocatable, dimension(:,:) :: m_indices
    contains
        procedure, public :: create => d2d_init
        procedure, public :: get_point_count => d2d_get_pt_count
        procedure, public :: get_triangle_count => d2d_get_tri_count
        procedure, public :: get_points_x => d2d_get_x_pts
        procedure, public :: get_points_y => d2d_get_y_pts
        procedure, public :: get_indices => d2d_get_tris
        procedure, public :: find_triangle => d2d_get_tri_with_pt
    end type
 
! ----------
    interface
        module subroutine d2d_init(this, x, y, err)
            class(delaunay_tri_2d), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: x, y
            class(errors), intent(inout), target, optional :: err
        end subroutine
 
        pure module function d2d_get_pt_count(this) result(rst)
            class(delaunay_tri_2d), intent(in) :: this
            integer(int32) :: rst
        end function
 
        pure module function d2d_get_tri_count(this) result(rst)
            class(delaunay_tri_2d), intent(in) :: this
            integer(int32) :: rst
        end function
 
        pure module function d2d_get_x_pts(this) result(rst)
            class(delaunay_tri_2d), intent(in) :: this
            real(real64), allocatable, dimension(:) :: rst
        end function
 
        pure module function d2d_get_y_pts(this) result(rst)
            class(delaunay_tri_2d), intent(in) :: this
            real(real64), allocatable, dimension(:) :: rst
        end function
 
        pure module function d2d_get_tris(this) result(rst)
            class(delaunay_tri_2d), intent(in) :: this
            integer(int32), allocatable, dimension(:,:) :: rst
        end function
 
        pure module function d2d_get_tri_with_pt(this, x, y) result(rst)
            class(delaunay_tri_2d), intent(in) :: this
            real(real64), intent(in) :: x, y
            integer(int32) :: rst
        end function
    end interface
 
! ******************************************************************************
! FPLOT_PLOT_DATA_TRI_2D.F90
! ------------------------------------------------------------------------------
    type, extends(plot_data_colored) :: plot_data_tri_2d
    private
        real(real64), allocatable, dimension(:) :: m_x
        real(real64), allocatable, dimension(:) :: m_y
        integer(int32), allocatable, dimension(:,:) :: m_indices
        real(real32) :: m_linewidth = 1.0
        integer(int32) :: m_linestyle = line_solid
    contains
        procedure, public :: get_data_string => pdt2d_get_data_cmd
        procedure, public :: get_command_string => pdt2d_get_cmd
        procedure, public :: define_data => pdt2d_define_data
        procedure, public :: get_line_width => pdt2d_get_line_width
        procedure, public :: set_line_width => pdt2d_set_line_width
        procedure, public :: get_line_style => pdt2d_get_line_style
        procedure, public :: set_line_style => pdt2d_set_line_style
    end type
 
! --------------------
    interface
        module function pdt2d_get_data_cmd(this) result(x)
            class(plot_data_tri_2d), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function pdt2d_get_cmd(this) result(x)
            class(plot_data_tri_2d), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module subroutine pdt2d_define_data(this, tri)
            class(plot_data_tri_2d), intent(inout) :: this
            class(delaunay_tri_2d), intent(in) :: tri
        end subroutine
 
        module function pdt2d_get_axes_cmd(this) result(x)
            class(plot_data_tri_2d), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        pure module function pdt2d_get_line_width(this) result(rst)
            class(plot_data_tri_2d), intent(in) :: this
            real(real32) :: rst
        end function
 
        module subroutine pdt2d_set_line_width(this, x)
            class(plot_data_tri_2d), intent(inout) :: this
            real(real32), intent(in) :: x
        end subroutine
 
        pure module function pdt2d_get_line_style(this) result(rst)
            class(plot_data_tri_2d), intent(in) :: this
            integer(int32) :: rst
        end function
 
        module subroutine pdt2d_set_line_style(this, x)
            class(plot_data_tri_2d), intent(inout) :: this
            integer(int32), intent(in) :: x
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_DELAUNAY_TRI_SURFACE.F90
! ------------------------------------------------------------------------------
    type, extends(delaunay_tri_2d) :: delaunay_tri_surface
    private
        real(real64), allocatable, dimension(:) :: m_z
    contains
        procedure, public :: define_function_values => dts_define_fcn
        procedure, public :: get_points_z => dts_get_z
        generic, public :: evaluate => dts_interp_1, dts_interp_2
 
        procedure :: dts_interp_1
        procedure :: dts_interp_2
    end type
 
! --------------------
    interface
        module subroutine dts_define_fcn(this, z, err)
            class(delaunay_tri_surface), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: z
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        pure module function dts_get_z(this) result(rst)
            class(delaunay_tri_surface), intent(in) :: this
            real(real64), allocatable, dimension(:) :: rst
        end function
 
        pure module function dts_interp_1(this, x, y) result(z)
            class(delaunay_tri_surface), intent(in) :: this
            real(real64), intent(in) :: x, y
            real(real64) :: z
        end function
 
        pure module function dts_interp_2(this, x, y) result(z)
            class(delaunay_tri_surface), intent(in) :: this
            real(real64), intent(in), dimension(:) :: x, y
            real(real64), allocatable, dimension(:) :: z
        end function
    end interface
 
! ******************************************************************************
! FPLOT_TRI_SURFACE_PLOT_DATA.F90
! ------------------------------------------------------------------------------
    type, extends(plot_data) :: tri_surface_plot_data
    private
        real(real64), allocatable, dimension(:) :: m_x
        real(real64), allocatable, dimension(:) :: m_y
        real(real64), allocatable, dimension(:) :: m_z
        integer(int32), allocatable, dimension(:,:) :: m_indices
        logical :: m_wireframe = .true.
    contains
        procedure, public :: get_data_string => tspd_get_data_cmd
        procedure, public :: get_command_string => tspd_get_cmd
        procedure, public :: get_use_wireframe => tspd_get_wireframe
        procedure, public :: set_use_wireframe => tspd_set_wireframe
        procedure, public :: define_data => tspd_define_data
    end type
 
! --------------------
    interface
        module function tspd_get_data_cmd(this) result(x)
            class(tri_surface_plot_data), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function tspd_get_cmd(this) result(x)
            class(tri_surface_plot_data), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        pure module function tspd_get_wireframe(this) result(rst)
            class(tri_surface_plot_data), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine tspd_set_wireframe(this, x)
            class(tri_surface_plot_data), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module subroutine tspd_define_data(this, tri)
            class(tri_surface_plot_data), intent(inout) :: this
            class(delaunay_tri_surface), intent(in) :: tri
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_VECTOR_FIELD_PLOT_DATA.F90
! ------------------------------------------------------------------------------
    ! REF:
    ! http://www.gnuplotting.org/vector-field-from-data-file/
    ! http://gnuplot.sourceforge.net/demo_5.4/vector.html
    ! http://www.gnuplot.info/docs_5.4/Gnuplot_5_4.pdf (pg 79)
 
    type, extends(plot_data_colored) :: vector_field_plot_data
    private
        real(real64), allocatable, dimension(:,:,:) :: m_data
        real(real64) :: m_arrowsize = 1.0d0
        logical :: m_filledheads = .false.
    contains
        procedure, public :: get_data_string => vfpd_get_data_cmd
        procedure, public :: get_command_string => vfpd_get_cmd
        procedure, public :: define_data => vfpd_define_data
        procedure, public :: get_arrow_size => vfpd_get_arrow_size
        procedure, public :: set_arrow_size => vfpd_set_arrow_size
        procedure, public :: get_fill_arrow => vfpd_get_fill_arrow
        procedure, public :: set_fill_arrow => vfpd_set_fill_arrow
        procedure, public :: get_use_data_dependent_colors => &
            vfpd_get_use_data_dependent_colors
    end type
 
! --------------------
    interface
         module function vfpd_get_data_cmd(this) result(x)
            class(vector_field_plot_data), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function vfpd_get_cmd(this) result(x)
            class(vector_field_plot_data), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module subroutine vfpd_define_data(this, x, y, dx, dy, c, err)
            class(vector_field_plot_data), intent(inout) :: this
            real(real64), intent(in), dimension(:,:) :: x, y, dx, dy
            real(real64), intent(in), dimension(:,:), optional :: c
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        pure module function vfpd_get_arrow_size(this) result(rst)
            class(vector_field_plot_data), intent(in) :: this
            real(real64) :: rst
        end function
 
        module subroutine vfpd_set_arrow_size(this, x)
            class(vector_field_plot_data), intent(inout) :: this
            real(real64), intent(in) :: x
        end subroutine
 
        pure module function vfpd_get_fill_arrow(this) result(rst)
            class(vector_field_plot_data), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine vfpd_set_fill_arrow(this, x)
            class(vector_field_plot_data), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function vfpd_get_use_data_dependent_colors(this) result(rst)
            class(vector_field_plot_data), intent(in) :: this
            logical :: rst
        end function
    end interface
 
! ******************************************************************************
! FPLOT_PLOT_POLAR.F90
! ------------------------------------------------------------------------------
    type, extends(plot) :: plot_polar
    private
        logical :: m_autoscale = .true.
        real(real64) :: m_minrad = 0.0d0
        real(real64) :: m_maxrad = 1.0d0
        character(len = :), allocatable :: m_thetastart 
        character(len = :), allocatable :: m_thetadirection
    contains
        final :: plr_clean_up
        procedure, public :: initialize => plr_init
        procedure, public :: get_command_string => plr_get_cmd
        procedure, public :: get_autoscale => plr_get_autoscale
        procedure, public :: set_autoscale => plr_set_autoscale
        procedure, public :: get_radial_limits => plr_get_limits
        procedure, public :: set_radial_limits => plr_set_limits
        procedure, public :: get_theta_start_position => plr_get_theta_start
        procedure, public :: set_theta_start_position => plr_set_theta_start
        procedure, public :: get_theta_direction => plr_get_theta_direction
        procedure, public :: set_theta_direction => plr_set_theta_direction
    end type
 
! --------------------
    interface
        module subroutine plr_clean_up(this)
            type(plot_polar), intent(inout) :: this
        end subroutine
 
        module subroutine plr_init(this, term, fname, err)
            class(plot_polar), intent(inout) :: this
            integer(int32), intent(in), optional :: term
            character(len = *), intent(in), optional :: fname
            class(errors), intent(inout), optional, target :: err
        end subroutine
 
        module function plr_get_cmd(this) result(x)
            class(plot_polar), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        pure module function plr_get_autoscale(this) result(rst)
            class(plot_polar), intent(in) :: this
            logical :: rst
        end function
 
        module subroutine plr_set_autoscale(this, x)
            class(plot_polar), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        pure module function plr_get_limits(this) result(rst)
            class(plot_polar), intent(in) :: this
            real(real64) :: rst(2)
        end function
 
        module subroutine plr_set_limits(this, x)
            class(plot_polar), intent(inout) :: this
            real(real64), intent(in) :: x(2)
        end subroutine
 
        pure module function plr_get_theta_start(this) result(rst)
            class(plot_polar), intent(in) :: this
            character(len = :), allocatable :: rst
        end function
 
        module subroutine plr_set_theta_start(this, x)
            class(plot_polar), intent(inout) :: this
            character(len = *), intent(in) :: x
        end subroutine
 
        pure module function plr_get_theta_direction(this) result(rst)
            class(plot_polar), intent(in) :: this
            character(len = :), allocatable :: rst
        end function
 
        module subroutine plr_set_theta_direction(this, x)
            class(plot_polar), intent(inout) :: this
            character(len = *), intent(in) :: x
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_FILLED_PLOT_DATA.F90
! ------------------------------------------------------------------------------
    type, extends(plot_data_colored) :: filled_plot_data
    private
        logical :: m_usey2 = .false.
        real(real64), allocatable, dimension(:,:) :: m_data
    contains
        procedure, public :: get_axes_string => fpd_get_axes_cmd
        procedure, public :: get_draw_against_y2 => fpd_get_draw_against_y2
        procedure, public :: set_draw_against_y2 => fpd_set_draw_against_y2
        procedure, public :: get_command_string => fpd_get_cmd
        procedure, public :: get_data_string => fpd_get_data_cmd
        procedure, public :: define_data => fpd_define_data
    end type
 
! --------------------
    interface
        module function fpd_get_axes_cmd(this) result(x)
            class(filled_plot_data), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        pure module function fpd_get_draw_against_y2(this) result(x)
            class(filled_plot_data), intent(in) :: this
            logical :: x
        end function
 
        module subroutine fpd_set_draw_against_y2(this, x)
            class(filled_plot_data), intent(inout) :: this
            logical, intent(in) :: x
        end subroutine
 
        module function fpd_get_cmd(this) result(x)
            class(filled_plot_data), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module function fpd_get_data_cmd(this) result(x)
            class(filled_plot_data), intent(in) :: this
            character(len = :), allocatable :: x
        end function
 
        module subroutine fpd_define_data(this, x, y, yc, err)
            class(filled_plot_data), intent(inout) :: this
            real(real64), intent(in), dimension(:) :: x, y, yc
            class(errors), intent(inout), optional, target :: err
        end subroutine
    end interface
 
! ******************************************************************************
! FPLOT_SIMPLIFY.F90
! ------------------------------------------------------------------------------
    interface simplify_polyline
        module procedure :: simplify_polyline_2d1
        module procedure :: simplify_polyline_3d1
        module procedure :: simplify_polyline_mtx
    end interface
 
    interface
        module function simplify_polyline_2d1(x, y, tol, err) result(ln)
            real(real64), intent(in), dimension(:) :: x, y
            real(real64), intent(in) :: tol
            class(errors), intent(inout), optional, target :: err
            real(real64), allocatable, dimension(:,:) :: ln
        end function
 
        module function simplify_polyline_3d1(x, y, z, tol, err) result(ln)
            real(real64), intent(in), dimension(:) :: x, y, z
            real(real64), intent(in) :: tol
            class(errors), intent(inout), optional, target :: err
            real(real64), allocatable, dimension(:,:) :: ln
        end function
 
        module function simplify_polyline_mtx(xy, tol, err) result(ln)
            real(real64), intent(in), dimension(:,:) :: xy
            real(real64), intent(in) :: tol
            class(errors), intent(inout), optional, target :: err
            real(real64), allocatable, dimension(:,:) :: ln
        end function
    end interface
 
! ------------------------------------------------------------------------------
end module