7.13 求解非线性方程组一组实根的蒙特卡洛法 nmtc.c

许士良常用算法程序集C语言,包括c++一些常用算法代码

#include "stdlib.h"
#include "math.h"
#include "3rnd1.c"
void nmtc(x,n,b,m,eps,f)
int n,m;
double x[],b,eps,(*f)();
{ 
	int k,i;
    double a,r,*y,z,z1;
    y=malloc(n*sizeof(double));
    a=b; k=1; r=1.0; z=(*f)(x,n);
    while (a>=eps)
    { 
		for (i=0; i<=n-1; i++)
			y[i]=-a+2.0*a*rnd1(&r)+x[i];
        z1=(*f)(y,n);
        k=k+1;
        if (z1>=z)
        { 
			if (k>m) 
			{ 
				k=1; a=a/2.0; 
			}
		}
        else
        { 
			k=1; 
            for (i=0; i<=n-1; i++) 
				x[i]=y[i];
            z=z1;
            if (z<eps)  
				return;
        }
    }
    return;
}