/* nag_real_gen_matrix_exp(f01ecc) Example Program.
 *
 * Copyright 2008, Numerical Algorithms Group.
 *
 * Mark 9, 2009.
 */
/* Pre-processor includes */
#include <stdio.h>
#include <math.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagf01.h>
#include <nagx04.h>

int main(int argc, char *argv[])
{
  FILE          *fpin, *fpout;
  char          *outfile = 0;
  /*Integer scalar and array declarations */
  Integer       exit_status = 0;
  Integer       i, j, n;
  Integer       pda;
  NagError      fail;
  /*Double scalar and array declarations */
  double        *a = 0;
  Nag_OrderType order;

  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, "%s\n",
          "nag_real_gen_matrix_exp (f01ecc) Example Program Results");
  fprintf(fpout, "\n");
  /* Skip heading in data file*/
  fscanf(fpin, "%*[^\n] ");
  fscanf(fpin, "%ld%*[^\n] ", &n);
  #ifdef NAG_COLUMN_MAJOR
  pda = n;
  #define A(I, J) a[(J-1)*pda + I-1]
  order = Nag_ColMajor;
  #else
  pda = n;
  #define A(I, J) a[(I-1)*pda + J-1]
  order = Nag_RowMajor;
  #endif
  if (!(a = NAG_ALLOC(pda*n, double)))
    {
      fprintf(fpout, "Allocation failure\n");
      exit_status = -1;
      goto END;
    }
  /* Read A from data file*/
  for (i = 1; i <= n; i++)
    {
      for (j = 1; j <= n; j++)
        fscanf(fpin, "%lf", &A(i, j));
    }
  fscanf(fpin, "%*[^\n] ");
  /* Find exp( A )*/
  /*
   * nag_real_gen_matrix_exp (f01ecc)
   * Real matrix exponential
   */
  nag_real_gen_matrix_exp(order, n, a, pda, &fail);
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_real_gen_matrix_exp (f01ecc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }
  /* Print solution*/
  /*
   * nag_gen_real_mat_print (x04cac)
   * Print real general matrix (easy-to-use)
   */
  if (outfile) fclose(fpout);
  nag_gen_real_mat_print(order, Nag_GeneralMatrix, Nag_NonUnitDiag, n, n,
                         a, pda, "Exp(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;
    }

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

  return exit_status;
}