Example description
/* nag_zherfs (f07mvc) 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, nrhs, pda, pdaf, pdb, pdx;
  Integer ferr_len, berr_len;
  Integer exit_status = 0;
  Nag_UploType uplo;
  NagError fail;
  Nag_OrderType order;
  /* Arrays */
  Integer *ipiv = 0;
  char nag_enum_arg[40];
  Complex *a = 0, *af = 0, *b = 0, *x = 0;
  double *berr = 0, *ferr = 0;

#ifdef NAG_COLUMN_MAJOR
#define A(I, J)  a[(J-1)*pda + I - 1]
#define AF(I, J) af[(J-1)*pdaf + I - 1]
#define B(I, J)  b[(J-1)*pdb + I - 1]
#define X(I, J)  x[(J-1)*pdx + I - 1]
  order = Nag_ColMajor;
#else
#define A(I, J)  a[(I-1)*pda + J - 1]
#define AF(I, J) af[(I-1)*pdaf + J - 1]
#define B(I, J)  b[(I-1)*pdb + J - 1]
#define X(I, J)  x[(I-1)*pdx + J - 1]
  order = Nag_RowMajor;
#endif

  INIT_FAIL(fail);

  printf("nag_zherfs (f07mvc) Example Program Results\n\n");
  /* Skip heading in data file */
  scanf("%*[^\n] ");
  scanf("%" NAG_IFMT "%" NAG_IFMT "%*[^\n] ", &n, &nrhs);
#ifdef NAG_COLUMN_MAJOR
  pda = n;
  pdaf = n;
  pdb = n;
  pdx = n;
#else
  pda = n;
  pdaf = n;
  pdb = nrhs;
  pdx = nrhs;
#endif

  ferr_len = nrhs;
  berr_len = nrhs;

  /* Allocate memory */
  if (!(ipiv = NAG_ALLOC(n, Integer)) ||
      !(a = NAG_ALLOC(n * n, Complex)) ||
      !(af = NAG_ALLOC(n * n, Complex)) ||
      !(b = NAG_ALLOC(n * nrhs, Complex)) ||
      !(x = NAG_ALLOC(n * nrhs, Complex)) ||
      !(berr = NAG_ALLOC(berr_len, double)) ||
      !(ferr = NAG_ALLOC(ferr_len, double)))
  {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }

  /* Read A and B from data file, and copy A to AF and B to X */
  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) {
    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 {
    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] ");
  }
  for (i = 1; i <= n; ++i) {
    for (j = 1; j <= nrhs; ++j)
      scanf(" ( %lf , %lf )", &B(i, j).re, &B(i, j).im);
  }
  scanf("%*[^\n] ");
  /* Copy A to AF and B to X   */
  if (uplo == Nag_Upper) {
    for (i = 1; i <= n; ++i) {
      for (j = i; j <= n; ++j) {
        AF(i, j).re = A(i, j).re;
        AF(i, j).im = A(i, j).im;
      }
    }
  }
  else {
    for (i = 1; i <= n; ++i) {
      for (j = 1; j <= i; ++j) {
        AF(i, j).re = A(i, j).re;
        AF(i, j).im = A(i, j).im;
      }
    }
  }
  for (i = 1; i <= n; ++i) {
    for (j = 1; j <= nrhs; ++j) {
      X(i, j).re = B(i, j).re;
      X(i, j).im = B(i, j).im;
    }
  }
  /* Factorize A in the array AF */
  /* nag_zhetrf (f07mrc).
   * Bunch-Kaufman factorization of complex Hermitian
   * indefinite matrix
   */
  nag_zhetrf(order, uplo, n, af, pdaf, ipiv, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_zhetrf (f07mrc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }
  /* Compute solution in the array X */
  /* nag_zhetrs (f07msc).
   * Solution of complex Hermitian indefinite system of linear
   * equations, multiple right-hand sides, matrix already
   * factorized by nag_zhetrf (f07mrc)
   */
  nag_zhetrs(order, uplo, n, nrhs, af, pdaf, ipiv, x, pdx, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_zhetrs (f07msc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }
  /* Improve solution, and compute backward errors and */
  /* estimated bounds on the forward errors */
  /* nag_zherfs (f07mvc).
   * Refined solution with error bounds of complex Hermitian
   * indefinite system of linear equations, multiple
   * right-hand sides
   */
  nag_zherfs(order, uplo, n, nrhs, a, pda, af, pdaf, ipiv,
             b, pdb, x, pdx, ferr, berr, &fail);
  if (fail.code != NE_NOERROR) {
    printf("Error from nag_zherfs (f07mvc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }
  /* Print solution */
  /* nag_gen_complx_mat_print_comp (x04dbc).
   * Print complex general matrix (comprehensive)
   */
  fflush(stdout);
  nag_gen_complx_mat_print_comp(order, Nag_GeneralMatrix, Nag_NonUnitDiag, n,
                                nrhs, x, pdx, Nag_BracketForm, "%7.4f",
                                "Solution(s)", 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;
  }
  printf("\nBackward errors (machine-dependent)\n");
  for (j = 1; j <= nrhs; ++j)
    printf("%11.1e%s", berr[j - 1], j % 4 == 0 ? "\n" : " ");
  printf("\nEstimated forward error bounds " "(machine-dependent)\n");
  for (j = 1; j <= nrhs; ++j)
    printf("%11.1e%s", ferr[j - 1], j % 4 == 0 ? "\n" : " ");
  printf("\n");
END:
  NAG_FREE(ipiv);
  NAG_FREE(a);
  NAG_FREE(af);
  NAG_FREE(b);
  NAG_FREE(x);
  NAG_FREE(berr);
  NAG_FREE(ferr);
  return exit_status;
}