xhqr.c

Numerical Recipes in C的源代码

/* Driver for routine hqr */

#include <stdio.h>
#define NRANSI
#include "nr.h"
#include "nrutil.h"

#define NP 5

int main(void)
{
	int i,j;
	static float c[NP][NP]=
		{1.0,2.0,0.0,0.0,0.0,
		-2.0,3.0,0.0,0.0,0.0,
		3.0,4.0,50.0,0.0,0.0,
		-4.0,5.0,-60.0,7.0,0.0,
		-5.0,6.0,-70.0,8.0,-9.0};
	float *wr,*wi,**a;

	wr=vector(1,NP);
	wi=vector(1,NP);
	a=convert_matrix(&c[0][0],1,NP,1,NP);
	printf("matrix:\n");
	for (i=1;i<=NP;i++) {
		for (j=1;j<=NP;j++) printf("%12.2f",a[i][j]);
		printf("\n");
	}
	balanc(a,NP);
	elmhes(a,NP);
	hqr(a,NP,wr,wi);
	printf("eigenvalues:\n");
	printf("%11s %16s \n","real","imag.");
	for (i=1;i<=NP;i++) printf("%15f %14f\n",wr[i],wi[i]);
	free_convert_matrix(a,1,NP,1,NP);
	free_vector(wi,1,NP);
	free_vector(wr,1,NP);
	return 0;
}
#undef NRANSI