rk4simu.c

来自「我们的大作业,包括runge-kutta法仿真,0-1分布,反变换的C语言原程序」· C语言 代码 · 共 40 行

  #include "stdio.h"
  #include "rk4sub.c"
  #include "math.h"
  #define  PI 3.1415926
  main()
  { int i;
    void  rkt1f(double,double [],int,double []);
    double t,h,y[2],z[2][22];

    y[0]=0; y[1]=PI;
    t=0.0; h=0.01;
    rkt1(t,y,2,h,22,z,rkt1f);
    printf("\n");
    printf("   t           solution            exact solution        the gap\n");
    for (i=0; i<22; i++)
    
      { t=i*h;
        printf("t=%-8.2f ",t);
       
          printf("y(%d)=%-16.10f  %-16.10f  %-16.10f\n ",i,z[0][i],sin(PI*t),z[0][i]-sin(PI*t));
        
      }
  }

  void rkt1f(t,y,n,d)
  int n;
  double t,y[],d[];
 
  { t=t; n=n;
    d[0]=y[1]; 
    d[1]=-PI*PI*y[0];
    return;
  }