xbcuint.c

Numerical Recipes in C的源代码

/* Driver for routine bcuint */

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

main()
{
	int i;
	float ansy,ansy1,ansy2,ey,ey1,ey2;
	float x1,x1l,x1u,x1x2,x2,x2l,x2u,xxyy;
	float y[5],y1[5],y12[5],y2[5];
	static float xx[]={0.0,0.0,2.0,2.0,0.0};
	static float yy[]={0.0,0.0,0.0,2.0,2.0};

	x1l=xx[1];
	x1u=xx[2];
	x2l=yy[1];
	x2u=yy[4];
	for (i=1;i<=4;i++) {
		xxyy=xx[i]*yy[i];
		y[i]=xxyy*xxyy;
		y1[i]=2.0*yy[i]*xxyy;
		y2[i]=2.0*xx[i]*xxyy;
		y12[i]=4.0*xxyy;
	}
	printf("\n%6s %8s %7s %11s %6s %10s %6s %10s \n\n",
		"x1","x2","y","expect","y1","expect","y2","expect");
	for (i=1;i<=10;i++) {
		x2=(x1=0.2*i);
		bcuint(y,y1,y2,y12,x1l,x1u,x2l,x2u,x1,x2,&ansy,&ansy1,&ansy2);
		x1x2=x1*x2;
		ey=x1x2*x1x2;
		ey1=2.0*x2*x1x2;
		ey2=2.0*x1*x1x2;
		printf("%8.4f %8.4f %8.4f %8.4f %8.4f %8.4f %8.4f %8.4f\n",
			x1,x2,ansy,ey,ansy1,ey1,ansy2,ey2);
	}
	return 0;
}