int main()
{
slong iter;
flint_rand_t state;
flint_printf("integrate_taylor....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 150 * arb_test_multiplier(); iter++)
{
acb_t ans, res, a, b;
arf_t inr, outr;
double t;
slong goal, prec;
acb_init(ans);
acb_init(res);
acb_init(a);
acb_init(b);
arf_init(inr);
arf_init(outr);
goal = 2 + n_randint(state, 300);
prec = 2 + n_randint(state, 300);
acb_randtest(a, state, 1 + n_randint(state, 200), 2);
acb_randtest(b, state, 1 + n_randint(state, 200), 2);
acb_cos(ans, a, prec);
acb_cos(res, b, prec);
acb_sub(ans, ans, res, prec);
t = (1 + n_randint(state, 20)) / 10.0;
arf_set_d(inr, t);
arf_set_d(outr, t + (1 + n_randint(state, 20)) / 5.0);
acb_calc_integrate_taylor(res, sin_x, NULL,
a, b, inr, outr, goal, prec);
if (!acb_overlaps(res, ans))
{
flint_printf("FAIL! (iter = %wd)\n", iter);
flint_printf("prec = %wd, goal = %wd\n", prec, goal);
flint_printf("inr = "); arf_printd(inr, 15); flint_printf("\n");
flint_printf("outr = "); arf_printd(outr, 15); flint_printf("\n");
flint_printf("a = "); acb_printd(a, 15); flint_printf("\n");
flint_printf("b = "); acb_printd(b, 15); flint_printf("\n");
flint_printf("res = "); acb_printd(res, 15); flint_printf("\n\n");
flint_printf("ans = "); acb_printd(ans, 15); flint_printf("\n\n");
abort();
}
acb_clear(ans);
acb_clear(res);
acb_clear(a);
acb_clear(b);
arf_clear(inr);
arf_clear(outr);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}
int main()
{
long iter;
flint_rand_t state;
printf("atan_arf....");
fflush(stdout);
flint_randinit(state);
/* self-consistency test */
for (iter = 0; iter < 5000; iter++)
{
arf_t x;
arb_t y1, y2;
long prec1, prec2, acc1, acc2;
prec1 = 2 + n_randint(state, 9000);
prec2 = 2 + n_randint(state, 9000);
arf_init(x);
arb_init(y1);
arb_init(y2);
arf_randtest_special(x, state, 1 + n_randint(state, 9000), 200);
arb_randtest_special(y1, state, 1 + n_randint(state, 9000), 200);
arb_randtest_special(y2, state, 1 + n_randint(state, 9000), 200);
if (n_randint(state, 2))
arf_add_ui(x, x, 1, 2 + n_randint(state, 9000), ARF_RND_DOWN);
arb_atan_arf(y1, x, prec1);
arb_atan_arf(y2, x, prec2);
if (!arb_overlaps(y1, y2))
{
printf("FAIL: overlap\n\n");
printf("prec1 = %ld, prec2 = %ld\n\n", prec1, prec2);
printf("x = "); arf_print(x); printf("\n\n");
printf("y1 = "); arb_print(y1); printf("\n\n");
printf("y2 = "); arb_print(y2); printf("\n\n");
abort();
}
acc1 = arb_rel_accuracy_bits(y1);
acc2 = arb_rel_accuracy_bits(y2);
if (!arf_is_nan(x))
{
if (acc1 < prec1 - 2 || acc2 < prec2 - 2)
{
printf("FAIL: accuracy\n\n");
printf("prec1 = %ld, prec2 = %ld\n\n", prec1, prec2);
printf("acc1 = %ld, acc2 = %ld\n\n", acc1, acc2);
printf("x = "); arf_printd(x, 50); printf("\n\n");
printf("y1 = "); arb_printd(y1, 50); printf("\n\n");
printf("y2 = "); arb_printd(y2, 50); printf("\n\n");
abort();
}
}
arf_clear(x);
arb_clear(y1);
arb_clear(y2);
}
flint_randclear(state);
flint_cleanup();
printf("PASS\n");
return EXIT_SUCCESS;
}
int main()
{
slong iter;
flint_rand_t state;
flint_printf("get_mpn_fixed_mod_pi4....");
fflush(stdout);
flint_randinit(state);
/* _flint_rand_init_gmp(state); */
for (iter = 0; iter < 100000 * arb_test_multiplier(); iter++)
{
arf_t x;
int octant;
fmpz_t q;
mp_ptr w;
arb_t wb, t, u;
mp_size_t wn;
slong prec, prec2;
int success;
mp_limb_t error;
prec = 2 + n_randint(state, 10000);
wn = 1 + n_randint(state, 200);
prec2 = FLINT_MAX(prec, wn * FLINT_BITS) + 100;
arf_init(x);
arb_init(wb);
arb_init(t);
arb_init(u);
fmpz_init(q);
w = flint_malloc(sizeof(mp_limb_t) * wn);
arf_randtest(x, state, prec, 14);
/* this should generate numbers close to multiples of pi/4 */
if (n_randint(state, 4) == 0)
{
arb_const_pi(t, prec);
arb_mul_2exp_si(t, t, -2);
fmpz_randtest(q, state, 200);
arb_mul_fmpz(t, t, q, prec);
arf_add(x, x, arb_midref(t), prec, ARF_RND_DOWN);
}
arf_abs(x, x);
success = _arb_get_mpn_fixed_mod_pi4(w, q, &octant, &error, x, wn);
if (success)
{
/* could round differently */
if (fmpz_fdiv_ui(q, 8) != octant)
{
flint_printf("bad octant\n");
abort();
}
_arf_set_mpn_fixed(arb_midref(wb), w, wn, wn, 0, FLINT_BITS * wn, ARB_RND);
mag_set_ui_2exp_si(arb_radref(wb), error, -FLINT_BITS * wn);
arb_const_pi(u, prec2);
arb_mul_2exp_si(u, u, -2);
arb_set(t, wb);
if (octant % 2 == 1)
arb_sub(t, u, t, prec2);
arb_addmul_fmpz(t, u, q, prec2);
if (!arb_contains_arf(t, x))
{
flint_printf("FAIL (containment)\n");
flint_printf("x = "); arf_printd(x, 50); flint_printf("\n\n");
flint_printf("q = "); fmpz_print(q); flint_printf("\n\n");
flint_printf("w = "); arb_printd(wb, 50); flint_printf("\n\n");
flint_printf("t = "); arb_printd(t, 50); flint_printf("\n\n");
abort();
}
arb_const_pi(t, prec2);
arb_mul_2exp_si(t, t, -2);
if (arf_sgn(arb_midref(wb)) < 0 ||
arf_cmp(arb_midref(wb), arb_midref(t)) >= 0)
{
flint_printf("FAIL (expected 0 <= w < pi/4)\n");
flint_printf("x = "); arf_printd(x, 50); flint_printf("\n\n");
flint_printf("w = "); arb_printd(wb, 50); flint_printf("\n\n");
abort();
}
}
flint_free(w);
fmpz_clear(q);
arf_clear(x);
arb_clear(wb);
arb_clear(t);
arb_clear(u);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}
int
acb_calc_integrate_taylor(acb_t res,
acb_calc_func_t func, void * param,
const acb_t a, const acb_t b,
const arf_t inner_radius,
const arf_t outer_radius,
long accuracy_goal, long prec)
{
long num_steps, step, N, bp;
int result;
acb_t delta, m, x, y1, y2, sum;
acb_ptr taylor_poly;
arf_t err;
acb_init(delta);
acb_init(m);
acb_init(x);
acb_init(y1);
acb_init(y2);
acb_init(sum);
arf_init(err);
acb_sub(delta, b, a, prec);
/* precision used for bounds calculations */
bp = MAG_BITS;
/* compute the number of steps */
{
arf_t t;
arf_init(t);
acb_get_abs_ubound_arf(t, delta, bp);
arf_div(t, t, inner_radius, bp, ARF_RND_UP);
arf_mul_2exp_si(t, t, -1);
num_steps = (long) (arf_get_d(t, ARF_RND_UP) + 1.0);
/* make sure it's not something absurd */
num_steps = FLINT_MIN(num_steps, 10 * prec);
num_steps = FLINT_MAX(num_steps, 1);
arf_clear(t);
}
result = ARB_CALC_SUCCESS;
acb_zero(sum);
for (step = 0; step < num_steps; step++)
{
/* midpoint of subinterval */
acb_mul_ui(m, delta, 2 * step + 1, prec);
acb_div_ui(m, m, 2 * num_steps, prec);
acb_add(m, m, a, prec);
if (arb_calc_verbose)
{
printf("integration point %ld/%ld: ", 2 * step + 1, 2 * num_steps);
acb_printd(m, 15); printf("\n");
}
/* evaluate at +/- x */
/* TODO: exactify m, and include error in x? */
acb_div_ui(x, delta, 2 * num_steps, prec);
/* compute bounds and number of terms to use */
{
arb_t cbound, xbound, rbound;
arf_t C, D, R, X, T;
double DD, TT, NN;
arb_init(cbound);
arb_init(xbound);
arb_init(rbound);
arf_init(C);
arf_init(D);
arf_init(R);
arf_init(X);
arf_init(T);
/* R is the outer radius */
arf_set(R, outer_radius);
/* X = upper bound for |x| */
acb_get_abs_ubound_arf(X, x, bp);
arb_set_arf(xbound, X);
/* Compute C(m,R). Important subtlety: due to rounding when
computing m, we will in general be farther than R away from
the integration path. But since acb_calc_cauchy_bound
actually integrates over the area traced by a complex
interval, it will catch any extra singularities (giving
an infinite bound). */
arb_set_arf(rbound, outer_radius);
acb_calc_cauchy_bound(cbound, func, param, m, rbound, 8, bp);
arf_set_mag(C, arb_radref(cbound));
arf_add(C, arb_midref(cbound), C, bp, ARF_RND_UP);
/* Sanity check: we need C < inf and R > X */
if (arf_is_finite(C) && arf_cmp(R, X) > 0)
{
/* Compute upper bound for D = C * R * X / (R - X) */
arf_mul(D, C, R, bp, ARF_RND_UP);
arf_mul(D, D, X, bp, ARF_RND_UP);
arf_sub(T, R, X, bp, ARF_RND_DOWN);
arf_div(D, D, T, bp, ARF_RND_UP);
/* Compute upper bound for T = (X / R) */
arf_div(T, X, R, bp, ARF_RND_UP);
/* Choose N */
/* TODO: use arf arithmetic to avoid overflow */
/* TODO: use relative accuracy (look at |f(m)|?) */
DD = arf_get_d(D, ARF_RND_UP);
TT = arf_get_d(T, ARF_RND_UP);
NN = -(accuracy_goal * 0.69314718055994530942 + log(DD)) / log(TT);
N = NN + 0.5;
N = FLINT_MIN(N, 100 * prec);
N = FLINT_MAX(N, 1);
/* Tail bound: D / (N + 1) * T^N */
{
mag_t TT;
mag_init(TT);
arf_get_mag(TT, T);
mag_pow_ui(TT, TT, N);
arf_set_mag(T, TT);
mag_clear(TT);
}
arf_mul(D, D, T, bp, ARF_RND_UP);
arf_div_ui(err, D, N + 1, bp, ARF_RND_UP);
}
else
{
N = 1;
arf_pos_inf(err);
result = ARB_CALC_NO_CONVERGENCE;
}
if (arb_calc_verbose)
{
printf("N = %ld; bound: ", N); arf_printd(err, 15); printf("\n");
printf("R: "); arf_printd(R, 15); printf("\n");
printf("C: "); arf_printd(C, 15); printf("\n");
printf("X: "); arf_printd(X, 15); printf("\n");
}
arb_clear(cbound);
arb_clear(xbound);
arb_clear(rbound);
arf_clear(C);
arf_clear(D);
arf_clear(R);
arf_clear(X);
arf_clear(T);
}
/* evaluate Taylor polynomial */
taylor_poly = _acb_vec_init(N + 1);
func(taylor_poly, m, param, N, prec);
_acb_poly_integral(taylor_poly, taylor_poly, N + 1, prec);
_acb_poly_evaluate(y2, taylor_poly, N + 1, x, prec);
acb_neg(x, x);
_acb_poly_evaluate(y1, taylor_poly, N + 1, x, prec);
acb_neg(x, x);
/* add truncation error */
arb_add_error_arf(acb_realref(y1), err);
arb_add_error_arf(acb_imagref(y1), err);
arb_add_error_arf(acb_realref(y2), err);
arb_add_error_arf(acb_imagref(y2), err);
acb_add(sum, sum, y2, prec);
acb_sub(sum, sum, y1, prec);
if (arb_calc_verbose)
{
printf("values: ");
acb_printd(y1, 15); printf(" ");
acb_printd(y2, 15); printf("\n");
}
_acb_vec_clear(taylor_poly, N + 1);
if (result == ARB_CALC_NO_CONVERGENCE)
break;
}
acb_set(res, sum);
acb_clear(delta);
acb_clear(m);
acb_clear(x);
acb_clear(y1);
acb_clear(y2);
acb_clear(sum);
arf_clear(err);
return result;
}