/* nag_dsum (f16elc) Example Program.
 *
 * Copyright 2014 Numerical Algorithms Group.
 *
 * Mark 9, 2009.
 */

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagf16.h>

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

  exit_status = 0;
  INIT_FAIL(fail);

  printf("nag_dsum (f16elc) Example Program Results\n\n");

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

  xlen = MAX(1, 1 + (n - 1)*ABS(incx));

  if (n > 0)
    {
      /* Allocate memory */
      if (!(x = NAG_ALLOC(xlen, double)))
        {
          printf("Allocation failure\n");
          exit_status = -1;
          goto END;
        }
    }
  else
    {
      printf("Invalid n\n");
      exit_status = 1;
      goto END;
    }
  /* Input vector x */
  for (i = 0; i < xlen; i = i + incx)
    scanf("%lf", &x[i]);
  scanf("%*[^\n] ");

  /* nag_dsum (f16elc).
   * Sum elements of a vector of doubles */
  sumval = nag_dsum(n, x, incx, &fail);

  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_dsum (f16elc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

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

 END:
  NAG_FREE(x);

  return exit_status;
}