/* nag_real_eigensystem(f02agc) Example Program
 *
 * Copyright 1989 Numerical Algorithms Group.
 *
 * Mark 1, 1990.
 */

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

#define NMAX 4
#define TDA NMAX
#define TDV NMAX
#define COMPLEX(A) A.re, A.im

int main(void)
{
  Integer  i, j, n;
  double a[NMAX][TDA];
  Complex r[NMAX], v[NMAX][TDV];
  Integer iter[NMAX];

  Vprintf("f02agc Example Program Results\n");
  /* Skip heading in data file */
  Vscanf("%*[^\n]");
  Vscanf("%ld", &n);

  if (n<1 || n>NMAX)
    {
      Vfprintf(stderr, "N is out of range: N = %5ld\n", n);
      return EXIT_FAILURE;
    }
  for (i=0; i<n; i++)
    for (j=0; j<n; j++)
      Vscanf("%lf", &a[i][j]);
  f02agc(n, &a[0][0], (Integer)TDA, r, &v[0][0],
         (Integer)TDV, iter, NAGERR_DEFAULT);
  Vprintf("Eigenvalues\n");
  for (i=0; i<n; i++)
    Vprintf("(%7.3f, %7.3f) \n", COMPLEX(r[i]));
  Vprintf("\nEigenvectors\n");
  for (i=0; i<n; i++)
    for (j=0; j<n; j++)
      Vprintf("(%7.3f, %7.3f) %s", COMPLEX(v[i][j]),
              (j%4==3 || j==n-1)? "\n" : " ");
  return EXIT_SUCCESS;
}