#include <math.h>
#include <gsl/gsl_spline.h>
#include <petscvec.h>
#include "cubature.h"

Functions
PetscErrorCode	conv2_same (Vec vA, int mA, int nA, Vec vB, int mB, int nB, Vec &vresult)
double	interp1_linear (double x, double Y, int N, double xi)
double	dblquad_cubature (integrand f, double ax, double bx, double ay, double by, double reqRelError, void *fdata)

Function Documentation

PetscErrorCode conv2_same	(	Vec	vA,
		int	mA,
		int	nA,
		Vec	vB,
		int	mB,
		int	nB,
		Vec &	vresult
	)

Functions like Matlab's conv2(A,B,'same').

Only works on sequential PETSc Vecs.

Works by naively (sans FFT) convolving two sequential Vecs A,B. Size of A is mA x nA. Size of B is mB x nB. Returns a result Vec which is the same size as A. Effectively pads by zero, in that the result matches the discrete but infinite case . (The infinite case is where A(i,j) and B(i,j) are defined for -inf < i,j < inf but A(i,j)=0 if i<0 or i>mA-1 or j<0 or j>nA-1 and B(i,j)=0 if i<0 or i>mB-1 or j<0 or j>nB-1.)

This operation is O(mA^2 nA^2), but an alternate FFT implementation would be O(mA nA log(mA nA)), presumably.

Definition at line 26 of file matlablike.cc.

Referenced by BedDeformLC::step().

double dblquad_cubature	(	integrand	f,
		double	ax,
		double	bx,
		double	ay,
		double	by,
		double	reqRelError,
		void *	fdata
	)

Functions like Matlab's dblquad() for 2D integrals. Wrapper for cubature by Steven Johnson.

The cubature code is used for double integration. It replaces iterated use of a single-variable adaptive rule as in Matlab's dblquad. cubature.{h|c} by Johnson is based on HIntLib by Rudolf Schuerer as well on GSL itself. cubature is GPLed.

Definition at line 67 of file matlablike.cc.

Referenced by BedDeformLC::alloc().

double interp1_linear	(	double *	x,
		double *	Y,
		int	N,
		double	xi
	)

Functions like Matlab's interp1. Wrapper for GSL 1D interpolation.

Compare Matlab's

 yi=interp1(x,Y,xi,'linear')

Also

 yi=interp1(x,Y,xi,'linear','extrap')

.

Does no input checking.

Definition at line 53 of file matlablike.cc.

Referenced by ge_integrand().