/* nag_real_lu(f03afc) Example Program
 *
 * Copyright 1990 Numerical Algorithms Group.
 *
 * Mark 2 revised, 1992.
 */

#include <nag.h>
#include <math.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nagf03.h>

#define NMAX 8
#define TDA NMAX

int main(void)
{
  double detf, two=2.0;
  Integer  i, dete, j, n;
  static NagError fail;
  double a[NMAX][TDA];
  Integer pivot[NMAX];

  Vprintf("f03afc Example Program Results\n");
  /* Skip heading in data file */
  Vscanf("%*[^\n]");
  Vscanf("%ld",&n);

  if (n>0 && n<=NMAX)
    {
      for (i=0; i<n; i++)
        for (j=0; j<n; j++)
          Vscanf("%lf",&a[i][j]);
      fail.print = TRUE;
      f03afc(n,&a[0][0],(Integer)TDA,pivot,&detf,&dete,&fail);
      if (fail.code!=NE_NOERROR)
        return EXIT_FAILURE;
      else
        {
          Vprintf("Array A after factorization\n");
          for (i=0; i<n; i++)
            for (j=0; j<n; j++)
              Vprintf("%9.4f%s",a[i][j],(j%8==7 || j==n-1) ? "\n" : " ");
          Vprintf("\nArray P\n");
          for (i=0; i<n; i++)
            Vprintf("%3ld%s",pivot[i],(i%8==7 || i==n-1) ? "\n" : " ");
          Vprintf("\ndetf = %9.4f  dete = %2ld\n", detf, dete);
          detf = detf * pow(two, (double)dete);
          Vprintf("\nValue of determinant = %9.4f\n", detf);
        }
    }
  return EXIT_SUCCESS;
}