NAG Library Manual, Mark 28.3
Interfaces:  FL   CL   CPP   AD 

NAG CL Interface Introduction
Example description
/* nag_specfun_gamma_log_complex (s14agc) Example Program.
 *
 * Copyright 2022 Numerical Algorithms Group.
 *
 * Mark 28.3, 2022.
 */

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

int main(void) {
  Integer exit_status = 0;
  Complex y, z;
  NagError fail;

  INIT_FAIL(fail);

  /* Skip heading in data file */
  scanf("%*[^\n]");
  printf("nag_specfun_gamma_log_complex (s14agc) Example Program Results\n");
  printf("     z                  ln(Gamma(z))\n");
  while (scanf(" (%lf,%lf)%*[^\n] ", &z.re, &z.im) != EOF)
  {
    /* nag_specfun_gamma_log_complex (s14agc).
     * Logarithm of the Gamma function ln Gamma(z)
     */
    y = nag_specfun_gamma_log_complex(z, &fail);
    if (fail.code == NE_NOERROR)
      printf("(%5.1f,%5.1f)   (%13.4e,%13.4e)\n", z.re, z.im, y.re, y.im);
    else {
      printf("Error from nag_specfun_gamma_log_complex (s14agc).\n%s\n",
             fail.message);
      exit_status = 1;
      goto END;
    }
  }

END:

  return exit_status;
}