xbcucof.c

Numerical Recipes in C的源代码

/* Driver for routine bcucof */

#include <stdio.h>
#include <math.h>
#include "nr.h"
#include "nrutil.h"

main()
{
	int i,j;
	float d1,d2,ee,x1x2;
	float y[5],y1[5],y2[5],y12[5],**c;
	static float x1[]={0.0,0.0,2.0,2.0,0.0};
	static float x2[]={0.0,0.0,0.0,2.0,2.0};

	c=matrix(1,4,1,4);
	d1=x1[2]-x1[1];
	d2=x2[4]-x2[1];
	for (i=1;i<=4;i++) {
		x1x2=x1[i]*x2[i];
		ee=exp(-x1x2);
		y[i]=x1x2*ee;
		y1[i]=x2[i]*(1.0-x1x2)*ee;
		y2[i]=x1[i]*(1.0-x1x2)*ee;
		y12[i]=(1.0-3.0*x1x2+x1x2*x1x2)*ee;
	}
	bcucof(y,y1,y2,y12,d1,d2,c);
	printf("\nCoefficients for bicubic interpolation:\n\n");
	for (i=1;i<=4;i++) {
		for (j=1;j<=4;j++) printf("%12.6f",c[i][j]);
		printf("\n");
	}
	free_matrix(c,1,4,1,4);
	return 0;
}