spline_interpolator Derived Type

type, public, extends(base_interpolator) :: spline_interpolator

Defines a type meant for performing cubic spline interpolation.

Contents

Type-Bound Procedures

initialize interpolate interpolate_value

Type-Bound Procedures

procedure, public :: initialize => si_init

private subroutine si_init(this, x, y, ibcbeg, ybcbeg, ibcend, ybcend, err)

Initializes the interpolation object.

Arguments

Type	Intent	Optional	Attributes		Name
class(spline_interpolator),	intent(inout)			::	this	The spline_interpolator object.
real(kind=real64),	intent(in),		dimension(:)	::	x	An N-element array containing the x-coordinate data in either monotonically increasing or decreasing order.
real(kind=real64),	intent(in),		dimension(:)	::	y	An N-element array containing the y-coordinate data.
integer(kind=int32),	intent(in),	optional		::	ibcbeg	An optional input that defines the nature of the boundary condition at the beginning of the spline. If no parameter, or an invalid parameter, is specified, the default condition (SPLINE_QUADRATIC_OVER_INTERVAL) is used. SPLINE_QUADRATIC_OVER_INTERVAL: The spline is quadratic over its initial interval. No value is required for ybcbeg. SPLINE_KNOWN_FIRST_DERIVATIVE: The spline's first derivative at its initial point is provided in ybcbeg. SPLINE_KNOWN_SECOND_DERIVATIVE: The spline's second derivative at its initial point is provided in ybcbeg. SPLINE_CONTINUOUS_THIRD_DERIVATIVE: The third derivative is continuous at x(2). No value is required for ybcbeg.
real(kind=real64),	intent(in),	optional		::	ybcbeg	If needed, the value of the initial point boundary condition. If needed, but not supplied, a default value of zero will be used.
integer(kind=int32),	intent(in),	optional		::	ibcend	An optional input that defines the nature of the boundary condition at the end of the spline. If no parameter, or an invalid parameter, is specified, the default condition (SPLINE_QUADRATIC_OVER_INTERVAL) is used. SPLINE_QUADRATIC_OVER_INTERVAL: The spline is quadratic over its final interval. No value is required for ybcend. SPLINE_KNOWN_FIRST_DERIVATIVE: The spline's first derivative at its final point is provided in ybcend. SPLINE_KNOWN_SECOND_DERIVATIVE: The spline's second derivative at its final point is provided in ybcend. SPLINE_CONTINUOUS_THIRD_DERIVATIVE: The third derivative is continuous at x(n-1). No value is required for ybcend.
real(kind=real64),	intent(in),	optional		::	ybcend	If needed, the value of the final point boundary condition. If needed, but not supplied, a default value of zero will be used.
class(errors),	intent(inout),	optional,	target	::	err	An error handling object.

procedure, public :: interpolate => bi_interp

private subroutine bi_interp(this, x, yi, err)

Performs the interpolation.

Arguments

Type	Intent	Optional	Attributes		Name
class(base_interpolator),	intent(inout)			::	this	The base_interpolator object.
real(kind=real64),	intent(in),		dimension(:)	::	x	An N-element array containing the x values at which to compute the interpolation.
real(kind=real64),	intent(out),		dimension(:)	::	yi	An N-element array containing the interpolated data.
class(errors),	intent(inout),	optional,	target	::	err	An error handling object.

procedure, public :: interpolate_value => si_raw_interp

private function si_raw_interp(this, x) result(rst)

Interpolates a single value.

Arguments

Type	Intent	Optional	Attributes		Name
class(spline_interpolator),	intent(inout)			::	this	The spline_interpolator object.
real(kind=real64),	intent(in)			::	x	The value at which to compute the interpolation.

Return Value real(kind=real64)

The interpolated value.