void arb_fib_fmpz(arb_t f, const fmpz_t n, slong prec)
{
arb_t t, u;
slong wp, sign, i;
if (fmpz_sgn(n) < 0)
{
fmpz_t m;
fmpz_init(m);
fmpz_neg(m, n);
arb_fib_fmpz(f, m, prec);
if (fmpz_is_even(m))
arb_neg(f, f);
fmpz_clear(m);
return;
}
if (fmpz_cmp_ui(n, 4) <= 0)
{
ulong x = fmpz_get_ui(n);
arb_set_ui(f, x - (x > 1));
return;
}
wp = ARF_PREC_ADD(prec, 3 * fmpz_bits(n));
arb_init(u);
arb_init(t);
arb_set_ui(f, UWORD(1));
arb_set_ui(u, UWORD(1));
sign = -1;
for (i = fmpz_flog_ui(n, UWORD(2)) - 1; i > 0; i--)
{
arb_mul(t, f, f, wp);
arb_add(f, f, u, wp);
arb_mul_2exp_si(f, f, -1);
arb_mul(f, f, f, wp);
arb_mul_2exp_si(f, f, 1);
arb_submul_ui(f, t, 3, wp);
arb_sub_si(f, f, 2 * sign, wp);
arb_mul_ui(u, t, 5, wp);
arb_add_si(u, u, 2 * sign, wp);
sign = 1;
if (fmpz_tstbit(n, i))
{
arb_set(t, f);
arb_add(f, f, u, wp);
arb_mul_2exp_si(f, f, -1);
arb_mul_2exp_si(t, t, 1);
arb_add(u, f, t, wp);
sign = -1;
}
}
if (fmpz_tstbit(n, 0))
{
arb_add(f, f, u, wp);
arb_mul_2exp_si(f, f, -1);
arb_mul(f, f, u, wp);
arb_sub_si(f, f, sign, prec);
}
else
{
arb_mul(f, f, u, prec);
}
arb_clear(u);
arb_clear(t);
}
int main()
{
slong iter;
flint_rand_t state;
flint_printf("sub_si....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 10000; iter++)
{
arb_t a, b, c, d;
slong x;
slong prec;
arb_init(a);
arb_init(b);
arb_init(c);
arb_init(d);
arb_randtest_special(a, state, 1 + n_randint(state, 2000), 100);
arb_randtest_special(b, state, 1 + n_randint(state, 2000), 100);
arb_randtest_special(c, state, 1 + n_randint(state, 2000), 100);
x = z_randtest(state);
prec = 2 + n_randint(state, 2000);
arb_set_si(b, x);
arb_sub_si(c, a, x, prec);
arb_sub(d, a, b, prec);
if (!arb_equal(c, d))
{
flint_printf("FAIL\n\n");
flint_printf("a = "); arb_print(a); flint_printf("\n\n");
flint_printf("b = "); arb_print(b); flint_printf("\n\n");
flint_printf("c = "); arb_print(c); flint_printf("\n\n");
flint_printf("d = "); arb_print(d); flint_printf("\n\n");
abort();
}
arb_clear(a);
arb_clear(b);
arb_clear(c);
arb_clear(d);
}
/* aliasing */
for (iter = 0; iter < 10000; iter++)
{
arb_t a, b, c;
slong x;
slong prec;
arb_init(a);
arb_init(b);
arb_init(c);
arb_randtest_special(a, state, 1 + n_randint(state, 2000), 100);
arb_randtest_special(b, state, 1 + n_randint(state, 2000), 100);
arb_randtest_special(c, state, 1 + n_randint(state, 2000), 100);
x = z_randtest(state);
prec = 2 + n_randint(state, 2000);
arb_set_si(b, x);
arb_sub_si(c, a, x, prec);
arb_sub_si(a, a, x, prec);
if (!arb_equal(a, c))
{
flint_printf("FAIL (aliasing)\n\n");
flint_printf("a = "); arb_print(a); flint_printf("\n\n");
flint_printf("b = "); arb_print(b); flint_printf("\n\n");
flint_printf("c = "); arb_print(c); flint_printf("\n\n");
abort();
}
arb_clear(a);
arb_clear(b);
arb_clear(c);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}
void
gamma_rate_mixture_summarize(
arb_ptr rate_mix_prior, arb_ptr rate_mix_rates, arb_ptr rate_mix_expect,
const gamma_rate_mixture_t x, enum rate_mixture_mode mode, slong prec)
{
slong i;
arb_ptr r;
arb_t p, q;
arb_init(p);
arb_init(q);
arb_set_d(p, x->invariable_prior);
arb_sub_si(q, p, 1, prec);
arb_neg(q, q);
/* the expectation is designed to be 1 */
arb_one(rate_mix_expect);
/* probabilities corresponding to gamma rate categories */
for (i = 0; i < x->gamma_categories; i++)
{
r = rate_mix_prior + i;
arb_div_si(r, q, x->gamma_categories, prec);
}
/* optional probability corresponding to the invariable category */
if (x->invariable_prior)
{
r = rate_mix_prior + x->gamma_categories;
arb_set(r, p);
}
/* set the discretized gamma rates */
{
arb_t s;
arb_init(s);
arb_set_d(s, x->gamma_shape);
if (mode == RATE_MIXTURE_GAMMA)
{
gamma_rates(
rate_mix_rates, x->gamma_categories, s, prec);
}
else if (mode == RATE_MIXTURE_GAMMA_MEDIAN)
{
normalized_median_gamma_rates(
rate_mix_rates, x->gamma_categories, s, prec);
}
else
{
abort(); /* assert */
}
arb_clear(s);
}
/* normalize the rates to account for a possible invariable category */
for (i = 0; i < x->gamma_categories; i++)
{
r = rate_mix_rates + i;
arb_div(r, r, q, prec);
}
arb_clear(p);
arb_clear(q);
}
