/* nag_zheevd (f08fqc) Example Program.
 *
 * Copyright 2001 Numerical Algorithms Group.
 *
 * Mark 7, 2001.
 */

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagf08.h>
#include <nagx04.h>
#include <naga02.h>

int main(void)
{
  /* Scalars */
  Integer       i, j, n, pda, w_len;
  Integer       exit_status = 0;
  NagError      fail;
  Nag_JobType   job;
  Nag_UploType  uplo;
  Nag_OrderType order;
  /* Arrays */
  char          nag_enum_arg[40];
  double        *w = 0;
  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_zheevd (f08fqc) Example Program Results\n\n");
  
  /* Skip heading in data file */
  scanf("%*[^\n]");
  scanf("%ld%*[^\n]", &n);
  pda = n;
  w_len = n;
  
  /* Allocate memory */
  if (!(a = NAG_ALLOC(n * n, Complex)) ||
      !(w = NAG_ALLOC(w_len, double)))
    {
      printf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }
  /* Read whether Upper or Lower part of A is stored */
  scanf("%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 A from data file */
  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] ");
    }
  
  /* Read type of job to be performed */
  scanf("%s%*[^\n]", nag_enum_arg);
  job = (Nag_JobType) nag_enum_name_to_value(nag_enum_arg);
  
  /* Calculate all the eigenvalues and eigenvectors of A using
   * nag_zheevd (f08fqc).
   * All eigenvalues and optionally all eigenvectors of
   * complex Hermitian matrix (divide-and-conquer)
   */
  nag_zheevd(order, job, uplo, n, a, pda, w, &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_zheevd (f08fqc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
  
  /* Normalize the eigenvectors */
  for(j=1; j<=n; j++)
    {
      for(i=n; i>=1; i--)
        {
          A(i, j) = nag_complex_divide(A(i, j),A(1, j));
        }
    }
  /* Print eigenvalues and eigenvectors */
  printf("Eigenvalues\n");
  for (i = 0; i < n; ++i) printf("   %5ld     %8.4f\n", i + 1, w[i]);
  printf("\n");
  /* nag_gen_complx_mat_print_comp (x04dbc).
   * Print complex general matrix (comprehensive)
   */
  fflush(stdout);
  nag_gen_complx_mat_print_comp(order, Nag_GeneralMatrix, Nag_NonUnitDiag, n,
                                n, a, pda, Nag_AboveForm, "%7.4f",
                                "Eigenvectors", Nag_IntegerLabels,
                                0, Nag_IntegerLabels, 0, 80, 0, 0, &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_gen_complx_mat_print_comp (x04dbc).\n%s\n",
	     fail.message);
      exit_status = 2;
      goto END;
    }
 END:
  if (a) NAG_FREE(a);
  if (w) NAG_FREE(w);
  return exit_status;
}