/* nag_dtrsm (f16yjc) 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(void)
{

  /* Scalars */
  double alpha;
  Integer exit_status, i, j, m, n, pda, pdb;

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

  /* Nag Types */
  NagError fail;
  Nag_SideType side;
  Nag_DiagType diag;
  Nag_OrderType order;
  Nag_TransType trans;
  Nag_UploType uplo;

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

  exit_status = 0;
  INIT_FAIL(fail);
  Vprintf( "nag_dtrsm (f16yjc) Example Program Results\n\n");

  /* Skip heading in data file */
  Vscanf("%*[^\n] ");
  /* Read the problem dimensions */
  Vscanf("%ld%ld%*[^\n] ",&m, &n);

#ifdef NAG_COLUMN_MAJOR
  pdb = m;
#else
  pdb = n;
#endif

  /* Read side */
  Vscanf("%s%*[^\n] ", nag_enum_arg);
  /* nag_enum_name_to_value(x04nac).
   * Converts NAG enum member name to value
   */
  side = nag_enum_name_to_value(nag_enum_arg);
  /* Read uplo */
  Vscanf("%s%*[^\n] ", nag_enum_arg);
  /* nag_enum_name_to_value(x04nac), see above. */
  uplo = nag_enum_name_to_value(nag_enum_arg);
  /* Read trans */
  Vscanf("%s%*[^\n] ", nag_enum_arg);
  /* nag_enum_name_to_value(x04nac), see above. */
  trans = nag_enum_name_to_value(nag_enum_arg);
  /* Read diag */
  Vscanf("%s%*[^\n] ", nag_enum_arg);
  /* nag_enum_name_to_value(x04nac), see above. */
  diag = nag_enum_name_to_value(nag_enum_arg);
  /* Read scalar parameters */
  Vscanf("%lf%*[^\n] ", &alpha);

  if (side == Nag_LeftSide) {
    pda = m;
  } else {
    pda = n;
  }

  if (n > 0)
    {

      /* Allocate memory */
      if ( !(a = NAG_ALLOC(pda*pda, double)) ||
           !(b = NAG_ALLOC(n*m, double)) )
        {
          Vprintf("Allocation failure\n");
          exit_status = -1;
          goto END;
        }
    }
  else
    {
      Vprintf("Invalid n\n");
      exit_status = 1;
      return exit_status;
    }

  /* Read A from data file */
  if (uplo == Nag_Upper)
    {
      for (i = 1; i <= pda; ++i)
        {
          for (j = i; j <= pda; ++j)
            Vscanf("%lf", &A(i,j));
        }
      Vscanf("%*[^\n] ");
    }
  else
    {
      for (i = 1; i <= pda; ++i)
        {
          for (j = 1; j <= i; ++j)
            Vscanf("%lf", &A(i,j));
        }
      Vscanf("%*[^\n] ");
    }

  /* Input matrix B */
  for (i = 1; i <= m; ++i)
    {
      for (j = 1; j <= n; ++j)
        Vscanf("%lf", &B(i,j));
    }

  /* nag_dtrsm(f16yjc).
   * Multiply matrix by inverse of Triangular matrix.
   *
   */
  nag_dtrsm(order, side, uplo, trans, diag, m, n, alpha, a, pda,
            b, pdb, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from dtrsm.\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

  /* Print the updated matrix B */
  /* nag_gen_real_mat_print (x04cac).
   * Print real general matrix (easy-to-use)
   */
  nag_gen_real_mat_print(order, Nag_GeneralMatrix, Nag_NonUnitDiag, m,
                         n, b, pdb, "Updated matrix B", 0, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_gen_real_mat_print (x04cac).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

 END:
  if (a) NAG_FREE(a);
  if (b) NAG_FREE(b);

  return exit_status;
}