fredex.c

适合大型数值计算代码 现在网络上已经找不到了 购买需要20$

#include <stdio.h>
#include <math.h>
#define NRANSI
#include "nrutil.h"
#define PI 3.14159265
#define N 40

int main(void)  /* Program fredex */
{
	void lubksb(float **a, int n, int *indx, float b[]);
	void ludcmp(float **a, int n, int *indx, float *d);
	void quadmx(float **a, int n);
	float **a,d,*g,x;
	int *indx,j;

	indx=ivector(1,N);
	a=matrix(1,N,1,N);
	g=vector(1,N);
	quadmx(a,N);
	ludcmp(a,N,indx,&d);
	for (j=1;j<=N;j++) g[j]=sin((j-1)*PI/(N-1));
	lubksb(a,N,indx,g);
	for (j=1;j<=N;j++) {
		x=(j-1)*PI/(N-1);
		printf("%6.2d %12.6f %12.6f\n",j,x,g[j]);
	}
	free_vector(g,1,N);
	free_matrix(a,1,N,1,N);
	free_ivector(indx,1,N);
	return 0;
}
#undef N
#undef PI
#undef NRANSI