Example description
/* nag_zpotrf (f07frc) Example Program.
 *
 * Copyright 2017 Numerical Algorithms Group.
 *
 * Mark 26.2, 2017.
 */

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagf07.h>
#include <nagx04.h>

int main(void)
{
  /* Scalars */
  Integer i, j, n, pda;
  Integer exit_status = 0;
  Nag_UploType uplo;
  Nag_MatrixType matrix;
  NagError fail;
  Nag_OrderType order;
  /* Arrays */
  char nag_enum_arg[40];
  Complex *a = 0;

#ifdef NAG_COLUMN_MAJOR
#define A(I, J) a[(J-1)*pda + I - 1]
  order = Nag_ColMajor;
#else
#define A(I, J) a[(I-1)*pda + J - 1]
  order = Nag_RowMajor;
#endif

  INIT_FAIL(fail);

  printf("nag_zpotrf (f07frc) Example Program Results\n\n");

  /* Skip heading in data file */
  scanf("%*[^\n] ");
  scanf("%" NAG_IFMT "%*[^\n] ", &n);
#ifdef NAG_COLUMN_MAJOR
  pda = n;
#else
  pda = n;
#endif

  /* Allocate memory */
  if (!(a = NAG_ALLOC(n * n, Complex)))
  {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }
  /* Read A from data file */
  scanf(" %39s%*[^\n] ", nag_enum_arg);
  /* nag_enum_name_to_value (x04nac).
   * Converts NAG enum member name to value
   */
  uplo = (Nag_UploType) nag_enum_name_to_value(nag_enum_arg);

  if (uplo == Nag_Upper) {
    matrix = Nag_UpperMatrix;
    for (i = 1; i <= n; ++i) {
      for (j = i; j <= n; ++j)
        scanf(" ( %lf , %lf )", &A(i, j).re, &A(i, j).im);
    }
    scanf("%*[^\n] ");
  }
  else {
    matrix = Nag_LowerMatrix;
    for (i = 1; i <= n; ++i) {
      for (j = 1; j <= i; ++j)
        scanf(" ( %lf , %lf )", &A(i, j).re, &A(i, j).im);
    }
    scanf("%*[^\n] ");
  }

  /* Factorize A */
  /* nag_zpotrf (f07frc).
   * Cholesky factorization of complex Hermitian
   * positive-definite matrix
   */
  nag_zpotrf(order, uplo, n, a, pda, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_zpotrf (f07frc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }
  /* Print factor */
  /* nag_gen_complx_mat_print_comp (x04dbc).
   * Print complex general matrix (comprehensive)
   */
  fflush(stdout);
  nag_gen_complx_mat_print_comp(order, matrix, Nag_NonUnitDiag, n, n, a, pda,
                                Nag_BracketForm, "%7.4f", "Factor",
                                Nag_IntegerLabels, 0, Nag_IntegerLabels, 0,
                                80, 0, 0, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_gen_complx_mat_print_comp (x04dbc).\n%s\n",
           fail.message);
    exit_status = 1;
    goto END;
  }
END:
  NAG_FREE(a);
  return exit_status;
}