13lman0.c

用途比较广泛的常用算法程序集C语言第13

  #include "stdio.h"
  #include "13lman.c"
  main()
  { int i,j,js;
    void eklm5();
    double p[3][3],x[200][3],y[200][1],g[3][1],t,s;
    static double f[3][3]={{1.0,0.05,0.00125},
                 {0.0,1.0,0.05},{0.0,0.0,1.0}};
    static double q[3][3]={{0.25,0.0,0.0},
                 {0.0,0.25,0.0},{0.0,0.0,0.25}};
    static double r[1][1]={0.25};
    static double h[1][3]={1.0,0.0,0.0};
    for (i=0; i<=2; i++)
    for (j=0; j<=2; j++) p[i][j]=0.0;
    for (i=0; i<=199; i++)
    for (j=0; j<=2; j++) x[i][j]=0.0;
    eklm5(200,y);
    for (i=0; i<=199; i++)
      { t=0.05*i;
        y[i][0]=5.0-2.0*t+3.0*t*t+y[i][0];
      }
    js=lman(3,1,200,f,q,r,h,y,x,p,g);
    if (js!=0)
      { printf("\n");
        printf("   t       s            y            ");
        printf("x(0)         x[1]         x(2)   \n");
        for (i=0; i<=199; i=i+5)
          { t=0.05*i; s=5.0-2.0*t+3.0*t*t;
            printf("%6.2f  %e  %e  %e  %e  %e\n",
                   t,s,y[i][0],x[i][0],x[i][1],x[i][2]);
          }
        printf("\n");
      }
  }

  static void eklm5(n,y)
  int n;
  double y[];
  { int i,j,m;
    double s,w,v,r,t;
    s=65536.0; w=2053.0; v=13849.0; r=0.0;
    for (i=0; i<=n-1; i++)
      { t=0.0;
        for (j=0; j<=11; j++)
          { r=w*r+v; m=r/s; r=r-m*s; t=t+r/s;}
        y[i]=0.5*(t-6.0);
      }
    return;
  }