/* nag_chi_sq_goodness_of_fit_test (g08cgc) Example Program.
 *
 * Copyright 2000 Numerical Algorithms Group.
 *
 * Mark 6, 2000.
 */

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagg01.h>
#include <nagg05.h>
#include <nagg08.h>

int main (void)
{
  char cdist[2];
  double chisq, *chisqi=0, *cint=0, *eval=0, p, *par=0, *prob=0, *x=0, xmax;
  double xmin;
  Integer i, iclass, *ifreq=0, init, n, nclass, ndf, npest;
  Integer exit_status=0;
  Nag_Distributions cdist_enum;
  NagError fail;
  Nag_ClassBoundary class_enum;

  INIT_FAIL(fail);
  Vprintf("g08cgc Example Program Results\n");

  /* Skip heading in data file */
  Vscanf("%*[^\n]");

  Vscanf("%ld %ld  %s %*[^\n] ", &n, &nclass, cdist);
  if (*cdist ==  'U')
    cdist_enum = Nag_Uniform;
  else if (*cdist == 'N')
    cdist_enum =  Nag_Normal;
  else if (*cdist ==  'G')
    cdist_enum = Nag_Gamma;
  else if (*cdist ==  'C')
    cdist_enum = Nag_ChiSquare;
  else if (*cdist ==  'E')
    cdist_enum =  Nag_Exponential;
  else if (*cdist ==  'A')
    cdist_enum = Nag_UserProb;
  else
    cdist_enum =  (Nag_Distributions)-999;
  if (!(x = NAG_ALLOC(n, double))
      || !(cint = NAG_ALLOC(nclass-1, double)  )
      || !(par = NAG_ALLOC(2, double))
      || !(ifreq = NAG_ALLOC(nclass, Integer)))
    {
      Vprintf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }
  for (i = 1; i <= 2; ++i)
    Vscanf("%lf", &par[i - 1]);
  npest = 0;
  /* Generate random numbers from a uniform distribution */
  init = 0;
  g05cbc(init);
  for (i = 0; i < n; i++)
    x[i] = g05dac(par[0], par[1]);
  iclass = 0;
  /* Determine suitable intervals */
  if (cdist_enum == Nag_Uniform)
    {
      iclass = 1;
      cint[0] = par[0] + (par[1] - par[0]) / nclass;
      for (i = 2; i <= nclass - 1; ++i)
        cint[i - 1] = cint[i - 2] + (par[1] - par[0]) / nclass;
    }
  if (iclass == 1)
    class_enum = Nag_ClassBoundaryUser;
  else
    class_enum = Nag_ClassBoundaryComp;


  g01aec(n, x, nclass, class_enum, cint, ifreq, &xmin, &xmax, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from g01aec.\n%s\n", fail.message);
      return 1;
    }

  if (!(chisqi = NAG_ALLOC(nclass, double))
      || !(eval = NAG_ALLOC(nclass, double))
      || !(prob = NAG_ALLOC(nclass, double)))
    {
      Vprintf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }
  g08cgc(nclass, ifreq, cint, cdist_enum, par, npest, prob, &chisq, &p, &ndf,
         eval, chisqi, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from g08cgc.\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
  Vprintf("\n");
  Vprintf("%s%10.4f\n", "Chi-squared test statistic   = ", chisq);
  Vprintf("%s%5ld\n", "Degrees of freedom.          = ", ndf);
  Vprintf("%s%10.4f\n", "Significance level           = ", p);
  Vprintf("\n");
  Vprintf("%s\n", "The contributions to the test statistic are :-");
  for (i = 1; i <= nclass; ++i)
    Vprintf("%10.4f\n", chisqi[i - 1]);
 END:
  if (x) NAG_FREE(x);
  if (cint) NAG_FREE(cint);
  if (par) NAG_FREE(par);
  if (ifreq) NAG_FREE(ifreq);
  if (chisqi) NAG_FREE(chisqi);
  if (eval) NAG_FREE(eval);
  if (prob) NAG_FREE(prob);
  return exit_status;
}