/* nag_dtr_load (f16qgc) Example Program.
 *
 * Copyright 2005 Numerical Algorithms Group.
 *
 * Mark 8, 2005.
 */

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagf16.h>
#include <nagx04.h>

int main(int argc, char *argv[])
{
  FILE           *fpin, *fpout;
  char           *outfile = 0;

  /* Scalars */
  double         alpha, diag;
  Integer        exit_status, n, pda;

  /* Arrays */
  double         *a = 0;
  char           nag_enum_arg[40];

  /* Nag Types */
  NagError       fail;
  Nag_MatrixType matrix;
  Nag_OrderType  order;
  Nag_UploType   uplo;

#ifdef NAG_COLUMN_MAJOR
#define A(I, J) a[(J-1)*pda + I - 1]
  order = Nag_ColMajor;
#else
#define A(I, J) a[(I-1)*pda + J - 1]
  order = Nag_RowMajor;
#endif

  exit_status = 0;
  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);
  (void) nag_example_file_io(argc, argv, "-nag_write", &outfile);
  fprintf(fpout, "nag_dtr_load (f16qgc) Example Program Results\n\n");

  /* Skip heading in data file */
  fscanf(fpin, "%*[^\n] ");
  /* Read the problem dimension */
  fscanf(fpin, "%ld%*[^\n] ", &n);
  /* Read uplo */
  fscanf(fpin, "%s%*[^\n] ", nag_enum_arg);
  /* nag_enum_name_to_value(x04nac).
   * Converts NAG enum member name to value
   */
  uplo = (Nag_UploType) nag_enum_name_to_value(nag_enum_arg);
  /* Read scalar parameters */
  fscanf(fpin, "%lf%lf%*[^\n] ", &alpha, &diag);

  pda = n;

  if (n > 0)
    {
      /* Allocate memory */
      if (!(a = NAG_ALLOC(n*pda, double)))
        {
          fprintf(fpout, "Allocation failure\n");
          exit_status = -1;
          goto END;
        }
    }
  else
    {
      fprintf(fpout, "Invalid n\n");
      exit_status = 1;
      return exit_status;
    }

  /* nag_dtr_load(f16qgc).
   * Triangular matrix initialise.
   *
   */
  nag_dtr_load(order, uplo, n, alpha, diag, a, pda, &fail);
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_dtr_load (f16qgc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

  /* Print output */
  /* nag_gen_real_mat_print (x04cac).
   * Print real general matrix (easy-to-use)
   */
  if (uplo == Nag_Upper)
    matrix = Nag_UpperMatrix;
  else
    matrix = Nag_LowerMatrix;

  if (outfile) fclose(fpout);
  nag_gen_real_mat_print(order, matrix, Nag_NonUnitDiag,
                         n, n, a, pda, "Matrix A",
                         outfile, &fail);
  if (outfile && !(fpout = fopen(outfile, "a")))
    {
      exit_status = 2;
      goto END;
    }
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_gen_real_mat_print (x04cac).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  if (a) NAG_FREE(a);

  return exit_status;
}