/* nag_all_regsn (g02eac) Example Program.
 *
 * Copyright 2002 Numerical Algorithms Group.
 *
 * Mark 7, 2002.
 */

#include <math.h>
#include <stdio.h>
#include <string.h>
#include <nag.h>
#include <nagx04.h>
#include <nag_stdlib.h>
#include <nagg02.h>

int main(int argc, char *argv[])
{
  FILE          *fpin, *fpout;

  /* Scalars */
  Integer       exit_status, free_vars, i, ii, j, m, n, nmod, pdx;
  NagError      fail;
  Nag_OrderType order;

  /* Arrays */
  char          **model = 0;
  const char    *var_names[] = { "DAY", "BOD", "TKN", "TS", "TVS", "COD" };
  double        *rss = 0, *x = 0, *y = 0, *wtptr = 0;
  Integer       *sx = 0, *mrank = 0, *nterms = 0;

  /* For iteration over model */
  Integer       model_index = 0;

#ifdef NAG_COLUMN_MAJOR
#define X(I, J) x[(J-1)*pdx + I - 1]
  order = Nag_ColMajor;
#else
#define X(I, J) x[(I-1)*pdx + J - 1]
  order = Nag_RowMajor;
#endif

  INIT_FAIL(fail);

  /* Check for command-line IO options */
  fpin = nag_example_file_io(argc, argv, "-data", NULL);
  fpout = nag_example_file_io(argc, argv, "-results", NULL);
  exit_status = 0;
  fprintf(fpout, "nag_all_regsn (g02eac) Example Program Results\n");

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

  fscanf(fpin, "%ld%ld%*[^\n] ", &n, &m);

  /* Allocate memory */
  if (!(x = NAG_ALLOC(n * m, double)) ||
      !(y = NAG_ALLOC(n, double)) ||
      !(sx = NAG_ALLOC(m, Integer)))
    {
      fprintf(fpout, "Allocation failure\n");
      exit_status = -1;
      goto END;
    }

#ifdef NAG_COLUMN_MAJOR
  pdx = n;
  order = Nag_ColMajor;
#else
  pdx = m;
  order = Nag_RowMajor;
#endif

  for (i = 1; i <= n; ++i)
    {
      for (j = 1; j <= m; ++j)
        fscanf(fpin, "%lf", &X(i, j));
      fscanf(fpin, "%lf%*[^\n] ", &y[i - 1]);
    }

  free_vars = 1;
  for (j = 1; j <= m; ++j)
    {
      fscanf(fpin, "%ld", &sx[j - 1]);
      if (sx[j - 1] == 1)
        {
          free_vars <<= 1;
        }
    }
  fscanf(fpin, "%*[^\n] ");

  if (!(model = NAG_ALLOC(free_vars*m, char *)) ||
      !(rss = NAG_ALLOC(free_vars, double)) ||
      !(mrank = NAG_ALLOC(free_vars, Integer)) ||
      !(nterms = NAG_ALLOC(free_vars, Integer)))
    {
      fprintf(fpout, "Allocation failure\n");
      exit_status = -1;
      goto END;
    }

  /* nag_all_regsn (g02eac).
   * Computes residual sums of squares for all possible linear
   * regressions for a set of independent variables
   */
  nag_all_regsn(order, Nag_MeanInclude, n, m, x, pdx, var_names, sx, y, wtptr,
                &nmod, model, rss, nterms, mrank, &fail);
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_all_regsn (g02eac).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

  fprintf(fpout, "\n");
  fprintf(fpout, "Number of     Rss    Rank         Model\n");
  fprintf(fpout, "parameters\n");
  for (i = 1; i <= nmod; ++i)
    {
      ii = nterms[i - 1];
      fprintf(fpout, "%8ld%11.4f%4ld   ", ii, rss[i-1],
              mrank[i-1]);
      for (j = 1; j <= ii; ++j)
        fprintf(fpout, "%-3.3s %s", model[model_index++],
                j%5 == 0 || j == 5?"\n":" ");
      fprintf(fpout, "\n");
    }
 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  if (rss) NAG_FREE(rss);
  if (x) NAG_FREE(x);
  if (y) NAG_FREE(y);
  if (sx) NAG_FREE(sx);
  if (mrank) NAG_FREE(mrank);
  if (nterms) NAG_FREE(nterms);
  if (model) NAG_FREE(model);
  return exit_status;
}