#include <stdio.h>
#include <math.h>
#define g 9.8
#define ndat 20
#define precision 0.5
 
float func(float t, float v0, float y0);
float calc_chi_2(float t[],float x[], float s[], float a, float b);
 
int main(void)
{
  FILE*fp;
  float t[ndat], exp_x[ndat], model_y[ndat], exp_y[ndat],error_y[ndat],error[ndat];
  int ih;
  if((fp=fopen("A16.0.csv","r")) !=NULL)
  {
    for(ih=0;ih<ndat;ih++)
      {
        fscanf(fp,"%f,%f,%f,%f,%f",&t[ih],&exp_x[ih],&model_y[ih],&exp_y[ih],&error_y[ih]);
        error[ih]=precision;
      }
    fclose(fp);
  }
  else{
    printf("File Open Error\n");
  }
  float v0=6.0,y0=5.0,chi_2;
  chi_2=calc_chi_2(t,exp_y,error,v0,y0);
  printf("chi square=%f,at v0=%f,y0=%f\n",chi_2,v0,y0);
  return 0;
}
 
//caluculate chi square//
float calc_chi_2(float t[],float x[], float s[], float a, float b)
{
  float chi_2=0;
  int ii;
  for(ii=0;ii<ndat;ii++)
    {
      chi_2+=(x[ii]-func(t[ii],a,b))*(x[ii]-func(t[ii],a,b))/(s[ii]*s[ii]);
      printf("%f,%f,%f,%f,%f\n",chi_2,t[ii],x[ii],func(t[ii],a,b),s[ii]);
    }
return chi_2;}
 
 
//function//
float func(float t, float v0, float y0)
{
  float y;
  y=-(g/2)*t*t+v0*t+y0;
  return y;
}
 

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