NAG Library Manual, Mark 30.2
Interfaces:  FL   CL   CPP   AD 

NAG CL Interface Introduction
Example description
/* nag_matop_complex_gen_matrix_exp (f01fcc) Example Program.
 *
 * Copyright 2024 Numerical Algorithms Group.
 *
 * Mark 30.2, 2024.
 */

#include <nag.h>

int main(void) {
  /* Scalars */
  Integer exit_status = 0;
  Integer pda;
  Integer i, j, n;

  /* Arrays */
  Complex *a = 0;

  /* NAG types */
  Nag_OrderType order;
  NagError fail;

  INIT_FAIL(fail);

  printf("nag_matop_complex_gen_matrix_exp (f01fcc) Example Program Results");
  printf("\n\n");
  fflush(stdout);

  /* Read matrix dimension from data file. */
  scanf("%*[^\n]%" NAG_IFMT "%*[^\n]", &n);

  pda = n;
  if (!(a = NAG_ALLOC((pda) * (n), Complex))) {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }

#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

  /* Read A from data file. */
  for (i = 1; i <= n; i++)
    for (j = 1; j <= n; j++)
      scanf(" ( %lf , %lf ) ", &A(i, j).re, &A(i, j).im);
  scanf("%*[^\n]");

  /* nag_matop_complex_gen_matrix_exp (f01fcc) - Complex matrix exponential */
  nag_matop_complex_gen_matrix_exp(order, n, a, pda, &fail);
  if (fail.code != NE_NOERROR) {
    printf("%s\n", fail.message);
    exit_status = 1;
    goto END;
  }

  /* nag_file_print_matrix_complex_gen (x04dac) - Print complex general matrix
   */
  nag_file_print_matrix_complex_gen(order, Nag_GeneralMatrix, Nag_NonUnitDiag,
                                    n, n, a, n, "Exp(A)", NULL, &fail);
  if (fail.code != NE_NOERROR) {
    printf("%s\n", fail.message);
    exit_status = 2;
    goto END;
  }

END:

  NAG_FREE(a);

  return exit_status;
}