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

NAG CL Interface Introduction
Example description
/* nag_blast_zsum (f16glc) Example Program.
 *
 * Copyright 2024 Numerical Algorithms Group.
 *
 * Mark 30.2, 2024.
 */

#include <nag.h>
#include <stdio.h>

int main(void) {
  /* Scalars */
  Integer exit_status, i, incx, ix, n;
  Complex sumval;
  /* Arrays */
  Complex *x = 0;
  /* Nag Types */
  NagError fail;

  exit_status = 0;
  INIT_FAIL(fail);

  printf("nag_blast_zsum (f16glc) Example Program Results\n\n");

  /* Skip heading in data file */
  scanf("%*[^\n] ");
  /* Read the number of elements and the increment */
  scanf("%" NAG_IFMT "%" NAG_IFMT "%*[^\n] ", &n, &incx);

  if (n > 0) {
    /* Allocate memory */
    if (!(x = NAG_ALLOC(MAX(1, 1 + (n - 1) * ABS(incx)), Complex))) {
      printf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }
  } else {
    printf("Invalid n\n");
    exit_status = 1;
    goto END;
  }

  /* Read the vector x and store forwards or backwards
   * as determined by incx. */
  for (i = 0, ix = (incx > 0 ? 0 : (1 - n) * incx); i < n; i++, ix += incx)
    scanf(" ( %lf , %lf ) ", &x[ix].re, &x[ix].im);
  scanf("%*[^\n] ");

  /* nag_blast_zsum (f16glc).
   * Sum elements of a vector of Complexes */
  sumval = nag_blast_zsum(n, x, incx, &fail);

  if (fail.code != NE_NOERROR) {
    printf("Error from nag_blast_zsum (f16glc).\n%s\n", fail.message);
    exit_status = 1;
    goto END;
  }

  /* Print the result. */
  printf("Sum of elements of x is (%9.5f,%9.5f)\n", sumval.re, sumval.im);

END:
  NAG_FREE(x);

  return exit_status;
}