regdat.c

来自「it is regression Algorithm in C/C++.」· C语言 代码 · 共 50 行

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define drand()   (rand()/((double)RAND_MAX+1))

#if DIM3

double f (double x, double y)
{
  return x*x*x +0.5*x*x +8*y;
}  /* f() */

#else

double f (double x, double y, double z)
{
  return 3*x*x*x*x -5*y*y*y -2*z*z*z +7*x*y;
}  /* f() */

#endif

int main (void)
{
  int    i;
  double x, y, z;

  srand(time(NULL));
  #if DIM3
  printf("x y z\n");
  #else
  printf("x y z f\n");
  #endif
  #if DIM3
  for (i = 0; i < 100; i++) {
  #else
  for (i = 0; i < 10000; i++) {
  #endif
    x = drand() *10 -5;
    y = drand() *10 -5;
    #if DIM3
    printf("%.16g %.16g %.16g\n", x, y, f(x, y));
    #else
    z = drand() *10 -5;
    printf("%.16g %.16g %.16g %.16g\n", x, y, z, f(x, y, z));
    #endif
  }
  return 0;
}  /* main() */