spir0.c

最小二乘法曲线拟合

  #include "stdio.h"
  #include "SPIR.C"
  #include "math.h"
  main()
  { int i;
    double x1[20],y1[20],a1[6],dt1[3];
    //void spir(double x[],double y[],int n,double a[],int m,double dt[]);
    for (i=0; i<=19; i++)
      { x1[i]=0.1*i;
        y1[i]=x1[i]-exp(-x1[i]);
      }
    spir(x1,y1,20,a1,6,dt1);
    printf("\n");
    for (i=0; i<=5; i++)
      printf("a(%2d)=%e\n",i,a1[i]);
    printf("\n");
    for (i=0; i<=2; i++)
      printf("dt(%2d)=%e  ",i,dt1[i]);
    printf("\n\n");
  }