/* nag_complex_cholesky (f01bnc) Example Program.
 *
 * Copyright 1990 Numerical Algorithms Group.
 *
 * Mark 1, 1990.
 * Mark 8 revised, 2004.
 */

#include <nag.h>
#include <math.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nagf01.h>

#define COMPLEX(A) A.re, A.im
#define A(I,J) a[(I)*tda + J]
int main(void)
{

  Complex *a=0;
  Integer exit_status=0, i, j, n, tda;
  NagError fail;
  double *p=0;

  INIT_FAIL(fail);
  Vprintf("nag_complex_cholesky (f01bnc) Example Program Results\n");
  /* Skip heading in data file */
  Vscanf("%*[^\n]");
  Vscanf("%ld", &n);
  if (n>=1)
    {
      if ( !( p = NAG_ALLOC(n, double))  ||
           !( a = NAG_ALLOC(n*n, Complex)) )
        {
          Vprintf("Allocation failure\n");
          exit_status = -1;
          goto END;
        }
      tda = n;
    }
  else
    {
      Vprintf("Invalid n.\n");
      exit_status = 1;
      return exit_status;
    }
  for (i=0; i<n; ++i)
    for (j=0; j<=i; ++j)
      Vscanf(" ( %lf,  %lf ) ", COMPLEX(&A(i,j)));
  /* nag_complex_cholesky (f01bnc).
   * UU^H factorization of complex Hermitian positive-definite
   * matrix
   */
  nag_complex_cholesky(n, a, tda, p, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_complex_cholesky (f01bnc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
  Vprintf("\n Upper triangle of Complex matrix U by rows\n");
  for (i=0; i<n; ++i)
    {
      Vprintf("\n");
      Vprintf("   (%7.4f,%9.4f)\n", 1.0/p[i], 0.0);
      for (j=i+1; j<n; ++j)
        Vprintf("   (%7.4f,%9.4f)\n", COMPLEX(A(i,j)));
    }
 END:
  if (p) NAG_FREE(p);
  if (a) NAG_FREE(a);
  return exit_status;
}