/* nag_trans_hessenberg_observer(g13ewc)  Example Program
 *
 * Copyright 1993 Numerical Algorithms Group
 *
 * Mark 3, 1993
 */

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nagg13.h>


#define NMAX 20
#define PMAX 20
#define TDA NMAX
#define TDC NMAX
#define TDU NMAX

int main(void)
{
  double a[NMAX][TDA];
  double c[PMAX][TDC];
  double u[NMAX][TDU];
  Integer i, j, n, p;
  Nag_ObserverForm reduceto;
  double zero = 0.0, one = 1.0;
  Integer nmax, pmax;

  Vprintf("g13ewc Example Program Results\n");

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

  nmax = NMAX;
  pmax = PMAX;

  Vscanf("%ld%ld",&n,&p);
  if (n<=0 || p<=0 ||
      n>nmax || p>pmax)
    {
      Vfprintf(stderr,"One of n or p is out of range n = %ld, p = %ld\n", n, p);
      return EXIT_FAILURE;
    }

  reduceto = Nag_UH_Observer;

  for (j = 0; j < n; ++j)
    for (i = 0; i < n; ++i)
      Vscanf("%lf", &a[i][j]);
  for (i = 0; i < p; ++i)
    for (j = 0; j < n; ++j)
      Vscanf("%lf", &c[i][j]);

  if (u) /* Initialise U as the identity matrix. */
    for (i = 0; i < n; ++i)
      {
        for (j = 0; j < n; ++j)
          u[i][j] = zero;
        u[i][i] = one;
      }

  /* Reduce the pair (A,C) to reduceto observer Hessenberg form. */
  g13ewc(n, p, reduceto, &a[0][0], (Integer)TDA, &c[0][0], (Integer)TDC,
         &u[0][0], (Integer)TDU,  NAGERR_DEFAULT);

  Vprintf("\nThe transformed state transition matrix is \n\n");
  for (i = 0; i < n; ++i)
    {
      for (j = 0; j < n; ++j)
        Vprintf("%8.4f ",a[i][j]);
      Vprintf("\n");
    }
  Vprintf("\nThe transformed input matrix is \n\n");
  for (i = 0; i < p; ++i)
    {
      for (j = 0; j < n; ++j)
        Vprintf("%8.4f ",c[i][j]);
      Vprintf("\n");
    }
  if (u)
    {
      Vprintf("\nThe transformation matrix that reduces (A,C) "
              "to observer Hessenberg form is \n\n");
      for (i = 0; i < n; ++i)
        {
          for (j = 0; j < n; ++j)
            Vprintf("%8.4f ",u[i][j]);
          Vprintf("\n");
        }
    }
  return EXIT_SUCCESS;
}