C++求矩阵的逆程序代码

C++求矩阵的逆程序代码

C inverse.c

C Source Code for "GRPP, A Scientific Programming Language

C Processor Designed for Lex and Yacc."

C Author: James Kent Blackburn

C Goddard Space Flight Center, Code 664.0, Greenbelt, MD. 20771

C Computers in Physics, Journal Section, Jan/Feb 1994

/*

Matrix Inversion using

LU Decomposition from

Numerical Recipes in C

Chapter 2

*/

#include <stdio.h>

#include <stdlib.h>

#include <math.h>

#define TINY 1.0e-20

void inverse(double**,int);

void ludcmp(double**, int, int*, double*);

void lubksb(double**, int, int*, double*);

double **matrix(int,int,int,int);

double *vector(int,int);

void free_matrix(double**,int,int,int,int);

void free_vector(double*,int,int);

void inverse(double **mat, int dim)

{

int i,j,*indx;

double **y,d,*col;

y = matrix(0,dim-1,0,dim-1);

indx = (int *)malloc((unsigned)(dim*sizeof(int)));

col = vector(0,dim-1);

ludcmp(mat,dim,indx,&d);

for (j=0;j<dim;j++)

{

for (i=0;i<dim;i++) col[i] = 0.0;

col[j] = 1.0;

lubksb(mat,dim,indx,col);