/* nag_complex_eigensystem_sel (f02gcc) Example Program.
 *
 * Copyright 1998 Numerical Algorithms Group.
 *
 * Mark 5, 1998.
 * Mark 8 revised, 2004.
 *
 */

#include <nag.h>
#include <nag_stdlib.h>
#include <stdio.h>
#include <nagf02.h>

#define MMAX 3

#define A(I,J) a[(I)*tda + J]
#define V(I,J) v[(I)*tdv + J]

int main(void)
{

  Complex *a=0, *v=0, *w=0;
  Integer exit_status=0, i, j, m, mest=MMAX, n, tda, tdv;
  NagError fail;
  double wl, wu;

  INIT_FAIL(fail);

  Vprintf("nag_complex_eigensystem_sel (f02gcc) Example Program Results\n");

  /* Skip heading in data file */
  Vscanf("%*[^\n]");

  Vscanf("%ld%lf%lf%*[^\n] ",&n, &wl, &wu);
  if (n>=0)
    {
      if ( !( a = NAG_ALLOC(n*n, Complex)) ||
           !( v = NAG_ALLOC(n*mest, Complex)) ||
           !( w = NAG_ALLOC(n, Complex)) )
        {
          Vprintf("Allocation failure\n");
          exit_status = -1;
          goto END;
        }
      tda = n;
      tdv = mest;

    }
  else
    {
      Vprintf("Invalid n.\n");
      exit_status = 1;
      return exit_status;
    }

  /* Read a from data file */
  for (i = 0; i < n; ++i)
    for (j = 0; j < n; ++j)
      Vscanf(" ( %lf, %lf ) ",&A(i,j).re,&A(i,j).im);

  /* Compute selected eigenvalues and eigenvectors of A */

  /* nag_complex_eigensystem_sel (f02gcc).
   * Computes selected eigenvalues and eigenvectors of a
   * complex general matrix
   */
  nag_complex_eigensystem_sel(Nag_Select_Modulus, n, a, tda, wl, wu, mest, &m,
                              w, v, tdv, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_complex_eigensystem_sel (f02gcc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  Vprintf("\n\nEigenvalues\n\n");
  for (i = 0; i < m; ++i)
    Vprintf("(%7.4f, %7.4f)%s",w[i].re,  w[i].im, (i+1)%2 == 0 ? "\n" : " ");

  Vprintf("\nEigenvectors\n");
  for (i=1; i<=m; i++)
    Vprintf("%15ld%s", i, i%m == 0 ?"\n" : "");

  for (i = 0; i < n; i++)
    {
      Vprintf("%ld  ", i + 1);
      for (j = 0; j < m; j++)
        Vprintf("(%8.4f, %8.4f)%s", V(i,j).re,
                V(i,j).im, (j + 1)%m == 0 ? "\n":"  ");
    }
 END:
  if (a) NAG_FREE(a);
  if (v) NAG_FREE(v);
  if (w) NAG_FREE(w);
  return exit_status;
}