/* nag_resgn_mult_linear_delete_var(g02dfc) Example Program
 *
 * Copyright 1991 Numerical Algorithms Group.
 *
 * Mark 2, 1991.
 */

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nagg02.h>

#define NMAX 12
#define MMAX 5
#define TDX MMAX
#define TDQ MMAX+1

int main(void)
{
  double   rss, tol;
  Integer  i, indx, ip, rank, j, m, n;
  double df;
  Boolean  svd;
  char     meanc, weight;
  Nag_IncludeMean  mean;
  double   b[MMAX], cov[MMAX*(MMAX+1)/2], h[NMAX], p[MMAX*(MMAX+2)],
  q[NMAX][MMAX+1], res[NMAX], se[MMAX], com_ar[5*(MMAX-1)+MMAX*MMAX],
  wt[NMAX], x[NMAX][MMAX], y[NMAX];
  double   *wtptr;
  Integer  sx[MMAX];

  Vprintf("g02dfc Example Program Results\n");
  /* Skip heading in data file */
  Vscanf("%*[^\n]");
  Vscanf("%ld %ld %c %c", &n, &m, &weight, &meanc);
  if (meanc=='m')
    mean = Nag_MeanInclude;
  else
    mean = Nag_MeanZero;

  if (weight=='w')
    wtptr = wt;
  else
    wtptr = (double *)0;

  if (n<=NMAX && m<MMAX)
    {
      if (wtptr)
        {
          for (i=0; i<n; ++i)
            {
              for (j=0; j<m; ++j)
                Vscanf("%lf", &x[i][j]);
              Vscanf("%lf%lf", &y[i], &wt[i]);
            }
        }
      else
        {
          for (i=0; i<n; ++i)
            {
              for (j=0; j<m; ++j)
                Vscanf("%lf", &x[i][j]);
              Vscanf("%lf", &y[i]);
            }
        }
      for (i=0; i<m; ++i)
        sx[i] = 1;
      ip = m;
      if (mean==Nag_MeanInclude)
        ip += 1;
      /* Set tolerance  */
      tol = 0.00001e0;
      g02dac(mean, n, &x[0][0], (Integer)TDX, m, sx, ip, y, wtptr, &rss,
             &df, b, se, cov, res, h, &q[0][0], (Integer)(TDQ), &svd, &rank,
             p, tol, com_ar, NAGERR_DEFAULT);
      Vprintf("Results from full model\n");
      if (svd)
        Vprintf("Model not of full rank\n\n");
      Vprintf("Residual sum of squares = %13.4e\n", rss);
      Vprintf("Degrees of freedom = %3.1f\n\n", df);
      while(scanf("%ld", &indx)!=EOF)
        {
          if (indx!=0)
            {
              g02dfc(ip, &q[0][0], (Integer)(TDQ), indx, &rss,
                     NAGERR_DEFAULT);

              ip = ip - 1;
              if (ip==0)
                Vprintf("No terms left in model\n");
              else
                {
                  Vprintf("Variable %4ld dropped\n", indx);
                  g02ddc(n, ip, &q[0][0], (Integer)(TDQ), &rss, &df, b, se,
                         cov, &svd, &rank, p, tol, NAGERR_DEFAULT);
                  Vprintf("Residual sum of squares = %13.4e\n", rss);
                  Vprintf("Degrees of freedom = %3.1f\n\n", df);
                  Vprintf("Parameter estimate   Standard error\n\n");
                  for (j=0; j<ip; j++)
                    Vprintf("%15.4e%15.4e\n", b[j], se[j]);
                }
            }
        }
    }
  else
    {
      Vfprintf(stderr, "One or both of m and n are out of range:"
               " m = %-3ld while  n = %-3ld\n", m, n);

      return EXIT_FAILURE;
    }
  return EXIT_SUCCESS;
}