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

#include <nag.h>
#include <nagx04.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(int argc, char *argv[])
{
  FILE     *fpin, *fpout;

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

  INIT_FAIL(fail);

  /* Check for command-line IO options */
  fpin = nag_example_file_io(argc, argv, "-data", NULL);
  fpout = nag_example_file_io(argc, argv, "-results", NULL);
  fprintf(fpout, "nag_complex_cholesky (f01bnc) Example Program Results\n");
  /* Skip heading in data file */
  fscanf(fpin, "%*[^\n]");
  fscanf(fpin, "%ld", &n);
  if (n >= 1)
    {
      if (!(p = NAG_ALLOC(n, double)) ||
          !(a = NAG_ALLOC(n*n, Complex)))
        {
          fprintf(fpout, "Allocation failure\n");
          exit_status = -1;
          goto END;
        }
      tda = n;
    }
  else
    {
      fprintf(fpout, "Invalid n.\n");
      exit_status = 1;
      return exit_status;
    }
  for (i = 0; i < n; ++i)
    for (j = 0; j <= i; ++j)
      fscanf(fpin, " ( %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)
    {
      fprintf(fpout, "Error from nag_complex_cholesky (f01bnc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }
  fprintf(fpout, "\n Upper triangle of Complex matrix U by rows\n");
  for (i = 0; i < n; ++i)
    {
      fprintf(fpout, "\n");
      fprintf(fpout, "   (%7.4f,%9.4f)\n", 1.0/p[i], 0.0);
      for (j = i+1; j < n; ++j)
        fprintf(fpout, "   (%7.4f,%9.4f)\n", COMPLEX(A(i, j)));
    }
 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  if (p) NAG_FREE(p);
  if (a) NAG_FREE(a);
  return exit_status;
}