runge-kutta.c

来自「我自己写的数值分析课程设计的源代码」· C语言 代码 · 共 32 行

#include<stdio.h>
#include<math.h>

#define n 100

double h,k1,k2,k3,k4;
double y[n]={0},x[0]={0};

void init()
{
	FILE *f;
	f=fopen("rk.txt","r");
	for(i=0;i<=3;i++)
		fscanf(f,"%f",x[i]);
	fclose(f);
}

double f(double a,double b)
{
	return 0;
}

void kutta(int m)
{
	k1=h*f(x[m-1],y[m-1]);
	k2=h*f(x[m-1]+1/2*h,y[m-1]+1/2*k1);
	k3=h*f(x[m-1]+1/2*h,y[m-1]+1/2*k2); 
	k4=h*f(x[m-1]+h,y[m-1]+k3);
	y[m]=y[m-1]+1/6*(k1+k2*2+k3*2+k4);
}