/* nag_real_cholesky(f03aec) Example Program
 *
 * Copyright 1990 Numerical Algorithms Group.
 *
 * Mark 1, 1990.
 */

#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, determ, a[NMAX][TDA], p[NMAX];
  Integer i, dete, j, n;
  static NagError fail;

  Vprintf("f03aec Example Program Results\n");
  /* Skip heading in data file */
  Vscanf("%*[^\n]");
  Vscanf("%ld\n",&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]);
  fail.print = TRUE;
  f03aec(n, &a[0][0], (Integer)TDA, p, &detf, &dete, &fail);
  if (fail.code != NE_NOERROR)
    return EXIT_FAILURE;
  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("%9.4f%s", p[i], (i%8==7 || i==n-1) ? "\n" : " ");
  Vprintf("\ndetf = %9.4f           dete = %2ld\n\n", detf, dete);
  determ = detf*pow(2.0,(double)dete);
  Vprintf("Value of determinant = %9.4f\n", determ);
  return EXIT_SUCCESS;
}