/* nag_dgeequ (f07afc) Example Program.
 *
 * Copyright 2014 Numerical Algorithms Group.
 *
 * Mark 23, 2011.
 */

#include <stdio.h>
#include <nag.h>
#include <nagx04.h>
#include <nag_stdlib.h>
#include <nagf07.h>
#include <nagx02.h>

int main(void)
{
  /* Scalars */
  double        amax, big, colcnd, rowcnd, small;
  Integer       i, j, m, n, pda;
  Integer       exit_status = 0;

  /* Arrays */
  double        *a = 0, *c = 0, *r = 0;

  /* Nag Types */
  NagError      fail;
  Nag_OrderType order;
  Nag_Boolean   scaled = Nag_FALSE;

#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

  INIT_FAIL(fail);

  printf("nag_dgeequ (f07afc) Example Program Results\n\n");

  /* Skip heading in data file */
  scanf("%*[^\n]");
  scanf("%ld%*[^\n]", &n);
  if (n < 0)
    {
      printf("Invalid n\n");
      exit_status = 1;
      return exit_status;
    }

  m = n;

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

  /* Allocate memory */
  if (!(a = NAG_ALLOC(m*n, double)) ||
      !(c = NAG_ALLOC(n, double)) ||
      !(r = NAG_ALLOC(m, double)))
    {
      printf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }

  /* Read the N by N matrix A from data file */
  for (i = 1; i <= n; ++i)
      for (j = 1; j <= n; ++j) scanf("%lf", &A(i, j));
  scanf("%*[^\n]");

  /* Print the matrix A using nag_gen_real_mat_print (x04cac) */
  fflush(stdout);
  nag_gen_real_mat_print(order, Nag_GeneralMatrix, Nag_NonUnitDiag, n, n, a,
                         pda, "Matrix A", 0, &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_gen_real_mat_print (x04cac).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
  printf("\n");

  /* Compute row and column scaling factors using nag_dgeequ (f07afc) */
  nag_dgeequ(order, m, n, a, pda, r, c, &rowcnd, &colcnd, &amax, &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_dgeequ (f07afc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

  /* Print rowcnd, colcnd, amax and the scale factors */
  printf("rowcnd = %10.1e, colcnd = %10.1e, amax = %10.1e\n\n", rowcnd,
          colcnd, amax);

  printf("Row scale factors\n");
  for (i = 1; i <= n; ++i)
    printf("%11.2e%s", r[i-1], i%7 == 0?"\n":" ");

  printf("\n\nColumn scale factors\n");
  for (i = 1; i <= n; ++i)
    printf("%11.2e%s", c[i-1], i%7 == 0?"\n":" ");
  printf("\n\n");

  /* Compute values close to underflow and overflow using 
   * nag_real_safe_small_number (x02amc), nag_machine_precision (x02ajc) and
   * nag_real_base (x02bhc)
   */
  small = nag_real_safe_small_number /  nag_machine_precision * nag_real_base;
  big = 1.0 / small;
  if (colcnd < 0.1)
    {
      scaled = Nag_TRUE;
      /* column scale A */
      for (j = 1; j <= n; ++j)
        for (i = 1; i <= n; ++i) A(i, j) = A(i, j) * c[j - 1];
    }
  if (rowcnd < 0.1 || amax < small || amax > big)
    {
      /* row scale A */
      scaled = Nag_TRUE;
      for (j = 1; j <= n; ++j)
        for (i = 1; i <= n; ++i) A(i, j) = r[i-1] * A(i, j);
    }
  if (scaled)
    {
      /* Print the row and column scaled matrix using
       * nag_gen_real_mat_print (x04cac)
       */
      fflush(stdout);
      nag_gen_real_mat_print(order, Nag_GeneralMatrix, Nag_NonUnitDiag, n, n,
                             a, pda, "Scaled matrix", 0, &fail);
      if (fail.code != NE_NOERROR)
        {
          printf("Error from nag_gen_real_mat_print (x04cac).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }
    }

 END:
  NAG_FREE(a);
  NAG_FREE(c);
  NAG_FREE(r);

  return exit_status;
}