/* nag_trans_hessenberg_controller(g13exc)  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 MMAX 20

#define TDA NMAX
#define TDB MMAX
#define TDU NMAX

int main(void)

{
  double a[NMAX][TDA];
  double b[NMAX][TDB];
  double u[NMAX][TDU];
  Integer i, j, m, n;
  Nag_ControllerForm reduceto;
  double zero = 0.0, one = 1.0;
  Integer nmax, mmax;

  Vprintf("g13exc Example Program Results\n");

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

  nmax = NMAX;
  mmax = MMAX;

  Vscanf("%ld%ld",&n,&m);
  if (n<=0 || m<=0 ||
      n>nmax || m>mmax)
    {
      Vfprintf(stderr, "One of n or m is out of range "
               "n = %ld, m = %ld\n", n, m);

      return EXIT_FAILURE;
    }

  reduceto = Nag_UH_Controller;

  for (j=0; j<n; ++j)
    for (i=0; i<n; ++i)
      Vscanf("%lf",&a[i][j]);
  for (j=0; j<m; ++j)
    for (i=0; i<n; ++i)
      Vscanf("%lf",&b[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 (B,A) to reduceto controller Hessenberg form. */
  g13exc(n, m,  reduceto, &a[0][0], (Integer)TDA, &b[0][0], (Integer)TDB,
         &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<n; ++i)
    {
      for (j=0; j<m; ++j)
        Vprintf("%8.4f ", b[i][j]);
      Vprintf("\n");
    }
  if (u)
    {
      Vprintf("\nThe matrix that reduces (B,A) to ");
      Vprintf("controller 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;
}