/* nag_rngs_corr_matrix (g05qbc) Example Program.
 *
 * Copyright 2001 Numerical Algorithms Group.
 *
 * Mark 7, 2001.
 */

#include <stdio.h>
#include <nag.h>
#include <nagx04.h>
#include <nag_stdlib.h>
#include <nagg05.h>

int main(int argc, char *argv[])
{
  FILE          *fpin, *fpout;
  /* Scalars */
  double        eps;
  Integer       i, igen, j, n;
  Integer       exit_status = 0;
  Integer       pdc;
  NagError      fail;
  Nag_OrderType order;

  /* Arrays */
  double        *c = 0, *d = 0;
  Integer       iseed[4];

#ifdef NAG_COLUMN_MAJOR
#define C(I, J) c[(J-1)*pdc + I - 1]
  order = Nag_ColMajor;
#else
#define C(I, J) c[(I-1)*pdc + 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);
  fprintf(fpout, "nag_rngs_corr_matrix (g05qbc) Example Program Results\n\n");

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

  /* Allocate memory */
  if (!(c = NAG_ALLOC(10 * 10, double)) ||
      !(d = NAG_ALLOC(10, double)))
    {
      fprintf(fpout, "Allocation failure\n");
      exit_status = -1;
      goto END;
    }

#ifdef NAG_COLUMN_MAJOR
  pdc = n;
#else
  pdc = n;
#endif

  if (n <= 10)
    {
      for (i = 0; i < n; ++i)
        {
          fscanf(fpin, "%lf", &d[i]);
        }
      fscanf(fpin, "%*[^\n] ");

      eps = 1e-4;

      /* igen identifies the stream. */
      igen = 1;
      /* Initialise the seed to a repeatable sequence */
      iseed[0] = 1762543;
      iseed[1] = 9324783;
      iseed[2] = 423446;
      iseed[3] = 742355;

      /* nag_rngs_init_repeatable (g05kbc).
       * Initialize seeds of a given generator for random number
       * generating functions (that pass seeds explicitly) to give
       * a repeatable sequence
       */
      nag_rngs_init_repeatable(&igen, iseed);

      /* nag_rngs_corr_matrix (g05qbc).
       * Computes a random correlation matrix
       */
      nag_rngs_corr_matrix(order, n, d, c, pdc, eps, igen, iseed, &fail);
      if (fail.code != NE_NOERROR)
        {
          fprintf(fpout, "Error from nag_rngs_corr_matrix (g05qbc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }
      for (i = 1; i <= n; ++i)
        {
          for (j = 1; j <= n; ++j)
            {
              fprintf(fpout, "%9.3f%s", C(i, j), j%3 == 0 || j == n?"\n":" ");
            }
        }
    }
 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  if (c) NAG_FREE(c);
  if (d) NAG_FREE(d);
  return exit_status;
}