void
acb_sinc_pi(acb_t res, const acb_t x, slong prec)
{
mag_t m;
acb_t t;
if (acb_is_zero(x))
{
acb_one(res);
return;
}
mag_init(m);
acb_init(t);
acb_get_mag_lower(m, x);
if (mag_cmp_2exp_si(m, -1) > 0)
{
acb_const_pi(t, prec + 4);
acb_mul(t, t, x, prec + 4);
acb_sin_pi(res, x, prec + 4);
acb_div(res, res, t, prec);
}
else
{
acb_const_pi(t, prec + 4);
acb_mul(t, t, x, prec + 4);
acb_sinc(res, t, prec);
}
mag_clear(m);
acb_clear(t);
}
int main()
{
slong iter;
flint_rand_t state;
flint_printf("sinc....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 10000 * arb_test_multiplier(); iter++)
{
acb_t a, b, c, d;
acb_init(a);
acb_init(b);
acb_init(c);
acb_init(d);
acb_randtest(a, state, 1 + n_randint(state, 400), 2 + n_randint(state, 100));
acb_randtest(b, state, 1 + n_randint(state, 400), 2 + n_randint(state, 100));
acb_randtest(c, state, 1 + n_randint(state, 400), 2 + n_randint(state, 100));
acb_sinc(b, a, 2 + n_randint(state, 400));
acb_sin(c, a, 2 + n_randint(state, 400));
acb_mul(d, b, a, 2 + n_randint(state, 400));
/* check consistency */
if (!acb_overlaps(c, d))
{
flint_printf("FAIL: overlap\n\n");
flint_printf("a = "); acb_printd(a, 30); flint_printf("\n\n");
flint_printf("b = "); acb_printd(b, 30); flint_printf("\n\n");
flint_printf("c = "); acb_printd(c, 30); flint_printf("\n\n");
flint_printf("d = "); acb_printd(d, 30); flint_printf("\n\n");
abort();
}
acb_set(c, a);
acb_sinc(c, c, 2 + n_randint(state, 400));
if (!acb_overlaps(b, c))
{
flint_printf("FAIL: aliasing\n\n");
flint_printf("a = "); acb_printd(a, 30); flint_printf("\n\n");
flint_printf("b = "); acb_printd(c, 30); flint_printf("\n\n");
flint_printf("c = "); acb_printd(c, 30); flint_printf("\n\n");
abort();
}
acb_clear(a);
acb_clear(b);
acb_clear(c);
acb_clear(d);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}