/* nag_zhecon (f07muc) Example Program.
 *
 * Copyright 2014 Numerical Algorithms Group.
 *
 * Mark 7, 2001.
 */

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <naga02.h>
#include <nagf07.h>
#include <nagf16.h>
#include <nagx02.h>

int main(void)
{
  /* Scalars */
  double        anorm, rcond;
  Integer       i, j, n, pda;
  Integer       exit_status = 0;
  Nag_UploType  uplo;
  NagError      fail;
  Nag_OrderType order;
  /* Arrays */
  Integer       *ipiv = 0;
  char          nag_enum_arg[40];
  Complex       *a = 0;

#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_zhecon (f07muc) Example Program Results\n\n");

  /* Skip heading in data file */
  scanf("%*[^\n] ");
  scanf("%ld%*[^\n] ", &n);
#ifdef NAG_COLUMN_MAJOR
  pda = n;
#else
  pda = n;
#endif

  /* Allocate memory */
  if (!(ipiv = NAG_ALLOC(n, Integer)) ||
      !(a = NAG_ALLOC(n * n, Complex)))
    {
      printf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }

  /* Read A from data file */
  scanf(" %39s%*[^\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);

  if (uplo == Nag_Upper)
    {
      for (i = 1; i <= n; ++i)
        {
          for (j = i; j <= n; ++j)
            scanf(" ( %lf , %lf )", &A(i, j).re, &A(i, j).im);
        }
      scanf("%*[^\n] ");
    }
  else
    {
      for (i = 1; i <= n; ++i)
        {
          for (j = 1; j <= i; ++j)
            scanf(" ( %lf , %lf )", &A(i, j).re, &A(i, j).im);
        }
      scanf("%*[^\n] ");
    }

  /* Compute norm of A */
  /* nag_zhe_norm (f16ucc).
   * 1-norm, infinity-norm, Frobenius norm, largest absolute
   * element, complex Hermitian matrix
   */
  nag_zhe_norm(order, Nag_OneNorm, uplo, n, a, pda, &anorm, &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_zhe_norm (f16ucc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
  /* Factorize A */

  /* nag_zhetrf (f07mrc).
   * Bunch-Kaufman factorization of complex Hermitian
   * indefinite matrix
   */
  nag_zhetrf(order, uplo, n, a, pda, ipiv, &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_zhetrf (f07mrc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
  /* Estimate condition number */
  /* nag_zhecon (f07muc).
   * Estimate condition number of complex Hermitian indefinite
   * matrix, matrix already factorized by nag_zhetrf (f07mrc)
   */
  nag_zhecon(order, uplo, n, a, pda, ipiv, anorm, &rcond,
             &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_zhecon (f07muc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
  /* nag_machine_precision (x02ajc).
   * The machine precision
   */
  if (rcond >= nag_machine_precision)
    printf("Estimate of condition number =%11.2e\n", 1.0/rcond);
  else
    printf("A is singular to working precision\n");
 END:
  NAG_FREE(ipiv);
  NAG_FREE(a);
  return exit_status;
}