NAG Library Manual, Mark 30
```/* nag_specfun_bessel_y_complex (s17dcc) Example Program.
*
* Copyright 2024 Numerical Algorithms Group.
*
* Mark 30.0, 2024.
*/

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

int main(void) {
Integer exit_status = 0;
Complex z, cy[2];
double fnu;
const Integer n = 2;
Integer nz;
Nag_ScaleResType scal;
char nag_enum_arg[40];
NagError fail;

INIT_FAIL(fail);

/* Skip heading in data file */
scanf("%*[^\n]");
printf("nag_specfun_bessel_y_complex (s17dcc) Example Program Results\n");
printf("Calling with n = %" NAG_IFMT "\n", n);
printf("   fnu           z              scal            cy[0]     "
"        cy[1]      nz\n");
while (scanf(" %lf (%lf,%lf) %39s%*[^\n] ", &fnu, &z.re, &z.im,
nag_enum_arg) != EOF) {
/* Convert scal character to enum */
scal = (Nag_ScaleResType)nag_enum_name_to_value(nag_enum_arg);

/* nag_specfun_bessel_y_complex (s17dcc).
* Bessel functions Y_(nu+a)(z), real a >= 0, complex z,
* nu = 0,1,2, ...
*/
nag_specfun_bessel_y_complex(fnu, z, n, scal, cy, &nz, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_specfun_bessel_y_complex (s17dcc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
printf("%7.4f (%7.3f,%7.3f) %-14s (%7.3f,%7.3f) (%7.3f,%7.3f) "
"%" NAG_IFMT "\n",
fnu, z.re, z.im, nag_enum_arg, cy[0].re, cy[0].im, cy[1].re,
cy[1].im, nz);
}

END:

return exit_status;
}
```