interp1Dexpl.c File Reference

Cubic spline interpolation in explicit form. More...

#include <stdlib.h>
#include <math.h>
#include "../ascot5.h"
#include "interp.h"
#include "spline.h"

Go to the source code of this file.

Functions
int	interp1Dexpl_init_coeff (real *c, real *f, int n_x, int bc_x, real x_min, real x_max)
	Calculate cubic spline interpolation coefficients for scalar 1D data.
void	interp1Dexpl_init_spline (interp1D_data *str, real *c, int n_x, int bc_x, real x_min, real x_max)
	Initialize a cubic spline.
a5err	interp1Dexpl_eval_f (real *f, interp1D_data *str, real x)
	Evaluate interpolated value of 1D scalar field.
a5err	interp1Dexpl_eval_df (real *f_df, interp1D_data *str, real x)
	Evaluate interpolated value of 1D and its 1st and 2nd derivatives.

Detailed Description

Cubic spline interpolation in explicit form.

Definition in file interp1Dexpl.c.

Function Documentation

interp1Dexpl_init_coeff()

int interp1Dexpl_init_coeff	(	real *	c,
		real *	f,
		int	n_x,
		int	bc_x,
		real	x_min,
		real	x_max )

Calculate cubic spline interpolation coefficients for scalar 1D data.

This function calculates the cubic spline interpolation coefficients and stores them in a pre-allocated array. Explicit cofficients are calculated.

Parameters

c	allocated array of length n_x*4 to store the coefficients
f	1D data to be interpolated
n_x	number of data points in the x axis
bc_x	boundary condition for the x axis
x_min	minimum value of the x axis
x_max	maximum value of the x axis

Definition at line 25 of file interp1Dexpl.c.

interp1Dexpl_init_spline()

void interp1Dexpl_init_spline	(	interp1D_data *	str,
		real *	c,
		int	n_x,
		int	bc_x,
		real	x_min,
		real	x_max )

Initialize a cubic spline.

Parameters

str	pointer to spline to be initialized
c	array where coefficients are stored
n_x	number of data points in the x direction
bc_x	boundary condition for x axis
x_min	minimum value of the x axis
x_max	maximum value of the x axis

Definition at line 52 of file interp1Dexpl.c.

interp1Dexpl_eval_f()

a5err interp1Dexpl_eval_f	(	real *	f,
		interp1D_data *	str,
		real	x )

Evaluate interpolated value of 1D scalar field.

This function evaluates the interpolated value of a 1D scalar field using bicubic spline interpolation coefficients of the explicit form.

Parameters

f	variable in which to place the evaluated value
str	data struct for data interpolation
x	x-coordinate

Returns

zero on success and one if x point is outside the domain.

Definition at line 81 of file interp1Dexpl.c.

interp1Dexpl_eval_df()

a5err interp1Dexpl_eval_df	(	real *	f_df,
		interp1D_data *	str,
		real	x )

Evaluate interpolated value of 1D and its 1st and 2nd derivatives.

This function evaluates the interpolated value of a 1D scalar field and its 1st and 2nd derivatives using bicubic spline interpolation coefficients of the explicit form.

The evaluated values are returned in an array with following elements:

• f_df[0] = f
• f_df[1] = f_x
• f_df[2] = f_xx

Parameters

f_df	array in which to place the evaluated values
str	data struct for data interpolation
x	x-coordinate

Returns

zero on success and one if (x,y) point is outside the grid.

Definition at line 131 of file interp1Dexpl.c.