static void bound_K(arb_t C, const arb_t AN, const arb_t B, const arb_t T, slong wp) { if (arb_is_zero(B) || arb_is_zero(T)) { arb_one(C); } else { arb_div(C, B, AN, wp); /* TODO: atan is dumb, should also bound by pi/2 */ arb_atan(C, C, wp); arb_mul(C, C, T, wp); if (arb_is_nonpositive(C)) arb_one(C); else arb_exp(C, C, wp); } }
int main() { slong iter; flint_rand_t state; flint_printf("atan...."); fflush(stdout); flint_randinit(state); /* Compare with MPFR */ for (iter = 0; iter < 10000 * arb_test_multiplier(); iter++) { arb_t a, b; fmpq_t q; mpfr_t t; slong prec = 2 + n_randint(state, 200); arb_init(a); arb_init(b); fmpq_init(q); mpfr_init2(t, prec + 100); arb_randtest(a, state, 1 + n_randint(state, 200), 3); arb_randtest(b, state, 1 + n_randint(state, 200), 3); arb_get_rand_fmpq(q, state, a, 1 + n_randint(state, 200)); fmpq_get_mpfr(t, q, MPFR_RNDN); mpfr_atan(t, t, MPFR_RNDN); arb_atan(b, a, prec); if (!arb_contains_mpfr(b, t)) { flint_printf("FAIL: containment\n\n"); flint_printf("a = "); arb_print(a); flint_printf("\n\n"); flint_printf("b = "); arb_print(b); flint_printf("\n\n"); flint_abort(); } arb_atan(a, a, prec); if (!arb_equal(a, b)) { flint_printf("FAIL: aliasing\n\n"); flint_abort(); } arb_clear(a); arb_clear(b); fmpq_clear(q); mpfr_clear(t); } /* Check large arguments. */ for (iter = 0; iter < 10000 * arb_test_multiplier(); iter++) { arb_t a, b, c, d; slong prec1, prec2; prec1 = 2 + n_randint(state, 1000); prec2 = prec1 + 30; arb_init(a); arb_init(b); arb_init(c); arb_init(d); arb_randtest_precise(a, state, 1 + n_randint(state, 1000), 100); arb_atan(b, a, prec1); arb_atan(c, a, prec2); if (!arb_overlaps(b, c)) { flint_printf("FAIL: overlap\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_abort(); } /* check tan(atan(x)) = x */ arb_sin_cos(c, d, b, prec1); arb_div(c, c, d, prec1); if (!arb_contains(c, a)) { flint_printf("FAIL: functional equation\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"); flint_abort(); } arb_clear(a); arb_clear(b); arb_clear(c); arb_clear(d); } /* Compare with MPFR, higher precision. */ for (iter = 0; iter < 200 * arb_test_multiplier(); iter++) { arb_t a, b; fmpq_t q; mpfr_t t; slong prec = 2 + n_randint(state, 5000); arb_init(a); arb_init(b); fmpq_init(q); mpfr_init2(t, prec + 100); arb_randtest(a, state, 1 + n_randint(state, 5000), 8); arb_randtest(b, state, 1 + n_randint(state, 5000), 8); arb_get_rand_fmpq(q, state, a, 1 + n_randint(state, 200)); fmpq_get_mpfr(t, q, MPFR_RNDN); mpfr_atan(t, t, MPFR_RNDN); arb_atan(b, a, prec); if (!arb_contains_mpfr(b, t)) { flint_printf("FAIL: containment\n\n"); flint_printf("a = "); arb_print(a); flint_printf("\n\n"); flint_printf("a = "); arb_printd(a, 50); flint_printf("\n\n"); flint_printf("a = "); arb_print(a); flint_printf("\n\n"); flint_printf("b = "); arb_printd(b, 50); flint_printf("\n\n"); flint_abort(); } arb_atan(a, a, prec); if (!arb_equal(a, b)) { flint_printf("FAIL: aliasing\n\n"); flint_abort(); } arb_clear(a); arb_clear(b); fmpq_clear(q); mpfr_clear(t); } /* Higher precision + large arguments. */ for (iter = 0; iter < 2000 * arb_test_multiplier(); iter++) { arb_t a, b, c, d; slong prec1, prec2; prec1 = 2 + n_randint(state, 5000); prec2 = prec1 + 30; arb_init(a); arb_init(b); arb_init(c); arb_init(d); arb_randtest_precise(a, state, 1 + n_randint(state, 5000), 100); arb_atan(b, a, prec1); arb_atan(c, a, prec2); if (!arb_overlaps(b, c)) { flint_printf("FAIL: overlap\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_abort(); } /* check tan(atan(x)) = x */ arb_sin_cos(c, d, b, prec1); arb_div(c, c, d, prec1); if (!arb_contains(c, a)) { flint_printf("FAIL: functional equation\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"); flint_abort(); } arb_clear(a); arb_clear(b); arb_clear(c); arb_clear(d); } /* Check wide arguments. */ for (iter = 0; iter < 100000 * arb_test_multiplier(); iter++) { arb_t a, b, c, d; arb_init(a); arb_init(b); arb_init(c); arb_init(d); arb_randtest_precise(a, state, 1 + n_randint(state, 1000), 100); arb_randtest_precise(b, state, 1 + n_randint(state, 1000), 100); if (n_randint(state, 2)) arb_add(a, a, b, 2 + n_randint(state, 1000)); arb_union(d, a, b, 2 + n_randint(state, 1000)); arb_atan(a, a, 2 + n_randint(state, 2000)); arb_atan(b, b, 2 + n_randint(state, 2000)); arb_atan(c, d, 2 + n_randint(state, 2000)); if (!arb_overlaps(c, a) || !arb_overlaps(c, b)) { flint_printf("FAIL: overlap\n\n"); flint_printf("d = "); arb_print(d); flint_printf("\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_abort(); } arb_clear(a); arb_clear(b); arb_clear(c); arb_clear(d); } flint_randclear(state); flint_cleanup(); flint_printf("PASS\n"); return EXIT_SUCCESS; }