void test_field1(flint_rand_t state) { /* tests in QQ[sqrt(5)] */ int iter; fmpq_t k; fmpq_poly_t p; arb_t emb; renf_t nf; renf_elem_t a; fmpq_poly_init(p); fmpq_poly_set_coeff_si(p, 2, 1); fmpq_poly_set_coeff_si(p, 1, -1); fmpq_poly_set_coeff_si(p, 0, -1); arb_init(emb); arb_set_d(emb, 1.61803398874989); arb_add_error_2exp_si(emb, -20); renf_init(nf, p, emb, 20 + n_randint(state, 20)); arb_clear(emb); renf_elem_init(a, nf); fmpq_init(k); /* (1+sqrt(5))/2 vs Fibonacci */ fmpq_poly_zero(p); fmpq_poly_set_coeff_si(p, 1, -1); for (iter = 1; iter < 50; iter++) { fprintf(stderr, "start iter = %d\n", iter); fflush(stderr); fmpz_fib_ui(fmpq_numref(k), iter+1); fmpz_fib_ui(fmpq_denref(k), iter); fmpq_poly_set_coeff_fmpq(p, 0, k); renf_elem_set_fmpq_poly(a, p, nf); check_ceil(a, nf, 1 - iter % 2, "sqrt(5)"); fprintf(stderr, "end\n"); fflush(stderr); } renf_elem_clear(a, nf); renf_clear(nf); fmpq_clear(k); fmpq_poly_clear(p); }
void arb_from_interval(arb_t x, const fmpz_t c, const slong k, const slong prec) { /* we build the ball that gives exactly (c 2^k, (c+1) 2^k) */ /* center: (2c+1) 2^(k-1) */ /* radius: 2^(k-1) */ if (prec <= 0 || prec < fmpz_bits(c) + 2) { fprintf(stderr, "not enough precision"); abort(); } arb_set_fmpz(x, c); arb_mul_2exp_si(x, x, 1); arb_add_si(x, x, 1, prec); arb_mul_2exp_si(x, x, k-1); arb_add_error_2exp_si(x, k-1); }
int main(int argc, char *argv[]) { acb_t s, t, a, b; mag_t tol; slong prec, goal; slong N; ulong k; int integral, ifrom, ito; int i, twice, havegoal, havetol; acb_calc_integrate_opt_t options; ifrom = ito = -1; for (i = 1; i < argc; i++) { if (!strcmp(argv[i], "-i")) { if (!strcmp(argv[i+1], "all")) { ifrom = 0; ito = NUM_INTEGRALS - 1; } else { ifrom = ito = atol(argv[i+1]); if (ito < 0 || ito >= NUM_INTEGRALS) flint_abort(); } } } if (ifrom == -1) { flint_printf("Compute integrals using acb_calc_integrate.\n"); flint_printf("Usage: integrals -i n [-prec p] [-tol eps] [-twice] [...]\n\n"); flint_printf("-i n - compute integral n (0 <= n <= %d), or \"-i all\"\n", NUM_INTEGRALS - 1); flint_printf("-prec p - precision in bits (default p = 64)\n"); flint_printf("-goal p - approximate relative accuracy goal (default p)\n"); flint_printf("-tol eps - approximate absolute error goal (default 2^-p)\n"); flint_printf("-twice - run twice (to see overhead of computing nodes)\n"); flint_printf("-heap - use heap for subinterval queue\n"); flint_printf("-verbose - show information\n"); flint_printf("-verbose2 - show more information\n"); flint_printf("-deg n - use quadrature degree up to n\n"); flint_printf("-eval n - limit number of function evaluations to n\n"); flint_printf("-depth n - limit subinterval queue size to n\n\n"); flint_printf("Implemented integrals:\n"); for (integral = 0; integral < NUM_INTEGRALS; integral++) flint_printf("I%d = %s\n", integral, descr[integral]); flint_printf("\n"); return 1; } acb_calc_integrate_opt_init(options); prec = 64; twice = 0; goal = 0; havetol = havegoal = 0; acb_init(a); acb_init(b); acb_init(s); acb_init(t); mag_init(tol); for (i = 1; i < argc; i++) { if (!strcmp(argv[i], "-prec")) { prec = atol(argv[i+1]); } else if (!strcmp(argv[i], "-twice")) { twice = 1; } else if (!strcmp(argv[i], "-goal")) { goal = atol(argv[i+1]); if (goal < 0) { flint_printf("expected goal >= 0\n"); return 1; } havegoal = 1; } else if (!strcmp(argv[i], "-tol")) { arb_t x; arb_init(x); arb_set_str(x, argv[i+1], 10); arb_get_mag(tol, x); arb_clear(x); havetol = 1; } else if (!strcmp(argv[i], "-deg")) { options->deg_limit = atol(argv[i+1]); } else if (!strcmp(argv[i], "-eval")) { options->eval_limit = atol(argv[i+1]); } else if (!strcmp(argv[i], "-depth")) { options->depth_limit = atol(argv[i+1]); } else if (!strcmp(argv[i], "-verbose")) { options->verbose = 1; } else if (!strcmp(argv[i], "-verbose2")) { options->verbose = 2; } else if (!strcmp(argv[i], "-heap")) { options->use_heap = 1; } } if (!havegoal) goal = prec; if (!havetol) mag_set_ui_2exp_si(tol, 1, -prec); for (integral = ifrom; integral <= ito; integral++) { flint_printf("I%d = %s ...\n", integral, descr[integral]); for (i = 0; i < 1 + twice; i++) { TIMEIT_ONCE_START switch (integral) { case 0: acb_set_d(a, 0); acb_set_d(b, 100); acb_calc_integrate(s, f_sin, NULL, a, b, goal, tol, options, prec); break; case 1: acb_set_d(a, 0); acb_set_d(b, 1); acb_calc_integrate(s, f_atanderiv, NULL, a, b, goal, tol, options, prec); acb_mul_2exp_si(s, s, 2); break; case 2: acb_set_d(a, 0); acb_one(b); acb_mul_2exp_si(b, b, goal); acb_calc_integrate(s, f_atanderiv, NULL, a, b, goal, tol, options, prec); arb_add_error_2exp_si(acb_realref(s), -goal); acb_mul_2exp_si(s, s, 1); break; case 3: acb_set_d(a, 0); acb_set_d(b, 1); acb_calc_integrate(s, f_circle, NULL, a, b, goal, tol, options, prec); acb_mul_2exp_si(s, s, 2); break; case 4: acb_set_d(a, 0); acb_set_d(b, 8); acb_calc_integrate(s, f_rump, NULL, a, b, goal, tol, options, prec); break; case 5: acb_set_d(a, 1); acb_set_d(b, 101); acb_calc_integrate(s, f_floor, NULL, a, b, goal, tol, options, prec); break; case 6: acb_set_d(a, 0); acb_set_d(b, 1); acb_calc_integrate(s, f_helfgott, NULL, a, b, goal, tol, options, prec); break; case 7: acb_zero(s); acb_set_d_d(a, -1.0, -1.0); acb_set_d_d(b, 2.0, -1.0); acb_calc_integrate(t, f_zeta, NULL, a, b, goal, tol, options, prec); acb_add(s, s, t, prec); acb_set_d_d(a, 2.0, -1.0); acb_set_d_d(b, 2.0, 1.0); acb_calc_integrate(t, f_zeta, NULL, a, b, goal, tol, options, prec); acb_add(s, s, t, prec); acb_set_d_d(a, 2.0, 1.0); acb_set_d_d(b, -1.0, 1.0); acb_calc_integrate(t, f_zeta, NULL, a, b, goal, tol, options, prec); acb_add(s, s, t, prec); acb_set_d_d(a, -1.0, 1.0); acb_set_d_d(b, -1.0, -1.0); acb_calc_integrate(t, f_zeta, NULL, a, b, goal, tol, options, prec); acb_add(s, s, t, prec); acb_const_pi(t, prec); acb_div(s, s, t, prec); acb_mul_2exp_si(s, s, -1); acb_div_onei(s, s); break; case 8: acb_set_d(a, 0); acb_set_d(b, 1); acb_calc_integrate(s, f_essing, NULL, a, b, goal, tol, options, prec); break; case 9: acb_set_d(a, 0); acb_set_d(b, 1); acb_calc_integrate(s, f_essing2, NULL, a, b, goal, tol, options, prec); break; case 10: acb_set_d(a, 0); acb_set_d(b, 10000); acb_calc_integrate(s, f_factorial1000, NULL, a, b, goal, tol, options, prec); break; case 11: acb_set_d_d(a, 1.0, 0.0); acb_set_d_d(b, 1.0, 1000.0); acb_calc_integrate(s, f_gamma, NULL, a, b, goal, tol, options, prec); break; case 12: acb_set_d(a, -10.0); acb_set_d(b, 10.0); acb_calc_integrate(s, f_sin_plus_small, NULL, a, b, goal, tol, options, prec); break; case 13: acb_set_d(a, -1020.0); acb_set_d(b, -1010.0); acb_calc_integrate(s, f_exp, NULL, a, b, goal, tol, options, prec); break; case 14: acb_set_d(a, 0); acb_set_d(b, ceil(sqrt(goal * 0.693147181) + 1.0)); acb_calc_integrate(s, f_gaussian, NULL, a, b, goal, tol, options, prec); acb_mul(b, b, b, prec); acb_neg(b, b); acb_exp(b, b, prec); arb_add_error(acb_realref(s), acb_realref(b)); break; case 15: acb_set_d(a, 0.0); acb_set_d(b, 1.0); acb_calc_integrate(s, f_spike, NULL, a, b, goal, tol, options, prec); break; case 16: acb_set_d(a, 0.0); acb_set_d(b, 8.0); acb_calc_integrate(s, f_monster, NULL, a, b, goal, tol, options, prec); break; case 17: acb_set_d(a, 0); acb_set_d(b, ceil(goal * 0.693147181 + 1.0)); acb_calc_integrate(s, f_sech, NULL, a, b, goal, tol, options, prec); acb_neg(b, b); acb_exp(b, b, prec); acb_mul_2exp_si(b, b, 1); arb_add_error(acb_realref(s), acb_realref(b)); break; case 18: acb_set_d(a, 0); acb_set_d(b, ceil(goal * 0.693147181 / 3.0 + 2.0)); acb_calc_integrate(s, f_sech3, NULL, a, b, goal, tol, options, prec); acb_neg(b, b); acb_mul_ui(b, b, 3, prec); acb_exp(b, b, prec); acb_mul_2exp_si(b, b, 3); acb_div_ui(b, b, 3, prec); arb_add_error(acb_realref(s), acb_realref(b)); break; case 19: if (goal < 0) abort(); /* error bound 2^-N (1+N) when truncated at 2^-N */ N = goal + FLINT_BIT_COUNT(goal); acb_one(a); acb_mul_2exp_si(a, a, -N); acb_one(b); acb_calc_integrate(s, f_log_div1p, NULL, a, b, goal, tol, options, prec); acb_set_ui(b, N + 1); acb_mul_2exp_si(b, b, -N); arb_add_error(acb_realref(s), acb_realref(b)); break; case 20: if (goal < 0) abort(); /* error bound (N+1) exp(-N) when truncated at N */ N = goal + FLINT_BIT_COUNT(goal); acb_zero(a); acb_set_ui(b, N); acb_calc_integrate(s, f_log_div1p_transformed, NULL, a, b, goal, tol, options, prec); acb_neg(b, b); acb_exp(b, b, prec); acb_mul_ui(b, b, N + 1, prec); arb_add_error(acb_realref(s), acb_realref(b)); break; case 21: acb_zero(s); N = 10; acb_set_d_d(a, 0.5, -0.5); acb_set_d_d(b, 0.5, 0.5); acb_calc_integrate(t, f_elliptic_p_laurent_n, &N, a, b, goal, tol, options, prec); acb_add(s, s, t, prec); acb_set_d_d(a, 0.5, 0.5); acb_set_d_d(b, -0.5, 0.5); acb_calc_integrate(t, f_elliptic_p_laurent_n, &N, a, b, goal, tol, options, prec); acb_add(s, s, t, prec); acb_set_d_d(a, -0.5, 0.5); acb_set_d_d(b, -0.5, -0.5); acb_calc_integrate(t, f_elliptic_p_laurent_n, &N, a, b, goal, tol, options, prec); acb_add(s, s, t, prec); acb_set_d_d(a, -0.5, -0.5); acb_set_d_d(b, 0.5, -0.5); acb_calc_integrate(t, f_elliptic_p_laurent_n, &N, a, b, goal, tol, options, prec); acb_add(s, s, t, prec); acb_const_pi(t, prec); acb_div(s, s, t, prec); acb_mul_2exp_si(s, s, -1); acb_div_onei(s, s); break; case 22: acb_zero(s); N = 1000; acb_set_d_d(a, 100.0, 0.0); acb_set_d_d(b, 100.0, N); acb_calc_integrate(t, f_zeta_frac, NULL, a, b, goal, tol, options, prec); acb_add(s, s, t, prec); acb_set_d_d(a, 100, N); acb_set_d_d(b, 0.5, N); acb_calc_integrate(t, f_zeta_frac, NULL, a, b, goal, tol, options, prec); acb_add(s, s, t, prec); acb_div_onei(s, s); arb_zero(acb_imagref(s)); acb_set_ui(t, N); acb_dirichlet_hardy_theta(t, t, NULL, NULL, 1, prec); acb_add(s, s, t, prec); acb_const_pi(t, prec); acb_div(s, s, t, prec); acb_add_ui(s, s, 1, prec); break; case 23: acb_set_d(a, 0.0); acb_set_d(b, 1000.0); acb_calc_integrate(s, f_lambertw, NULL, a, b, goal, tol, options, prec); break; case 24: acb_set_d(a, 0.0); acb_const_pi(b, prec); acb_calc_integrate(s, f_max_sin_cos, NULL, a, b, goal, tol, options, prec); break; case 25: acb_set_si(a, -1); acb_set_si(b, 1); acb_calc_integrate(s, f_erf_bent, NULL, a, b, goal, tol, options, prec); break; case 26: acb_set_si(a, -10); acb_set_si(b, 10); acb_calc_integrate(s, f_airy_ai, NULL, a, b, goal, tol, options, prec); break; case 27: acb_set_si(a, 0); acb_set_si(b, 10); acb_calc_integrate(s, f_horror, NULL, a, b, goal, tol, options, prec); break; case 28: acb_set_d_d(a, -1, -1); acb_set_d_d(b, -1, 1); acb_calc_integrate(s, f_sqrt, NULL, a, b, goal, tol, options, prec); break; case 29: acb_set_d(a, 0); acb_set_d(b, ceil(sqrt(goal * 0.693147181) + 1.0)); acb_calc_integrate(s, f_gaussian_twist, NULL, a, b, goal, tol, options, prec); acb_mul(b, b, b, prec); acb_neg(b, b); acb_exp(b, b, prec); arb_add_error(acb_realref(s), acb_realref(b)); arb_add_error(acb_imagref(s), acb_realref(b)); break; case 30: acb_set_d(a, 0); acb_set_d(b, ceil(goal * 0.693147181 + 1.0)); acb_calc_integrate(s, f_exp_airy, NULL, a, b, goal, tol, options, prec); acb_neg(b, b); acb_exp(b, b, prec); acb_mul_2exp_si(b, b, 1); arb_add_error(acb_realref(s), acb_realref(b)); break; case 31: acb_zero(a); acb_const_pi(b, prec); acb_calc_integrate(s, f_sin_cos_frac, NULL, a, b, goal, tol, options, prec); break; case 32: acb_zero(a); acb_set_ui(b, 3); acb_calc_integrate(s, f_sin_near_essing, NULL, a, b, goal, tol, options, prec); break; case 33: acb_zero(a); acb_zero(b); k = 3; scaled_bessel_select_N(acb_realref(b), k, prec); acb_calc_integrate(s, f_scaled_bessel, &k, a, b, goal, tol, options, prec); scaled_bessel_tail_bound(acb_realref(a), k, acb_realref(b), prec); arb_add_error(acb_realref(s), acb_realref(a)); break; case 34: acb_zero(a); acb_zero(b); k = 15; scaled_bessel_select_N(acb_realref(b), k, prec); acb_calc_integrate(s, f_scaled_bessel, &k, a, b, goal, tol, options, prec); scaled_bessel_tail_bound(acb_realref(a), k, acb_realref(b), prec); arb_add_error(acb_realref(s), acb_realref(a)); break; case 35: acb_set_d_d(a, -1, -1); acb_set_d_d(b, -1, 1); acb_calc_integrate(s, f_rsqrt, NULL, a, b, goal, tol, options, prec); break; default: abort(); } TIMEIT_ONCE_STOP } flint_printf("I%d = ", integral); acb_printn(s, 3.333 * prec, 0); flint_printf("\n\n"); } acb_clear(a); acb_clear(b); acb_clear(s); acb_clear(t); mag_clear(tol); flint_cleanup(); return 0; }
int main() { long iter; flint_rand_t state; printf("add_error...."); fflush(stdout); flint_randinit(state); for (iter = 0; iter < 10000; iter++) { arb_t a, b, c; arf_t m, r; arb_init(a); arb_init(b); arb_init(c); arf_init(m); arf_init(r); arb_randtest_special(a, state, 1 + n_randint(state, 2000), 10); arb_randtest_special(b, state, 1 + n_randint(state, 2000), 10); arb_randtest_special(c, state, 1 + n_randint(state, 2000), 10); arf_randtest_special(m, state, 1 + n_randint(state, 2000), 10); arf_randtest_special(r, state, 1 + n_randint(state, 2000), 10); /* c = a plus error bounds */ arb_set(c, a); arf_set(arb_midref(b), m); arf_get_mag(arb_radref(b), r); arb_add_error(c, b); /* b = a + random point */ arb_set(b, a); if (n_randint(state, 2)) arf_add(arb_midref(b), arb_midref(b), m, ARF_PREC_EXACT, ARF_RND_DOWN); else arf_sub(arb_midref(b), arb_midref(b), m, ARF_PREC_EXACT, ARF_RND_DOWN); if (n_randint(state, 2)) arf_add(arb_midref(b), arb_midref(b), r, ARF_PREC_EXACT, ARF_RND_DOWN); else arf_sub(arb_midref(b), arb_midref(b), r, ARF_PREC_EXACT, ARF_RND_DOWN); /* should this be done differently? */ if (arf_is_nan(arb_midref(b))) arf_zero(arb_midref(b)); if (!arb_contains(c, b)) { printf("FAIL (arb_add_error)\n\n"); printf("a = "); arb_printn(a, 50, 0); printf("\n\n"); printf("b = "); arb_printn(b, 50, 0); printf("\n\n"); printf("c = "); arb_printn(c, 50, 0); printf("\n\n"); abort(); } arb_clear(a); arb_clear(b); arb_clear(c); arf_clear(m); arf_clear(r); } for (iter = 0; iter < 10000; iter++) { arb_t a, b, c; arf_t m; arb_init(a); arb_init(b); arb_init(c); arf_init(m); arb_randtest_special(a, state, 1 + n_randint(state, 2000), 10); arb_randtest_special(b, state, 1 + n_randint(state, 2000), 10); arb_randtest_special(c, state, 1 + n_randint(state, 2000), 10); arf_randtest_special(m, state, 1 + n_randint(state, 2000), 10); /* c = a plus error bounds */ arb_set(c, a); arb_add_error_arf(c, m); /* b = a + random point */ arb_set(b, a); if (n_randint(state, 2)) arf_add(arb_midref(b), arb_midref(b), m, ARF_PREC_EXACT, ARF_RND_DOWN); else arf_sub(arb_midref(b), arb_midref(b), m, ARF_PREC_EXACT, ARF_RND_DOWN); /* should this be done differently? */ if (arf_is_nan(arb_midref(b))) arf_zero(arb_midref(b)); if (!arb_contains(c, b)) { printf("FAIL (arb_add_error_arf)\n\n"); printf("a = "); arb_printn(a, 50, 0); printf("\n\n"); printf("b = "); arb_printn(b, 50, 0); printf("\n\n"); printf("c = "); arb_printn(c, 50, 0); printf("\n\n"); abort(); } arb_clear(a); arb_clear(b); arb_clear(c); arf_clear(m); } for (iter = 0; iter < 10000; iter++) { arb_t a, b, c; arf_t t; mag_t r; arb_init(a); arb_init(b); arb_init(c); mag_init(r); arf_init(t); arb_randtest_special(a, state, 1 + n_randint(state, 2000), 10); arb_randtest_special(b, state, 1 + n_randint(state, 2000), 10); mag_randtest(r, state, 10); /* c = a plus error bounds */ arb_set(c, a); arb_add_error_mag(c, r); /* b = a + random point */ arb_set(b, a); arf_set_mag(t, r); if (n_randint(state, 2)) arf_add(arb_midref(b), arb_midref(b), t, ARF_PREC_EXACT, ARF_RND_DOWN); else arf_sub(arb_midref(b), arb_midref(b), t, ARF_PREC_EXACT, ARF_RND_DOWN); /* should this be done differently? */ if (arf_is_nan(arb_midref(b))) arf_zero(arb_midref(b)); if (!arb_contains(c, b)) { printf("FAIL (arb_add_error_mag)\n\n"); printf("a = "); arb_printn(a, 50, 0); printf("\n\n"); printf("b = "); arb_printn(b, 50, 0); printf("\n\n"); printf("c = "); arb_printn(c, 50, 0); printf("\n\n"); abort(); } arb_clear(a); arb_clear(b); arb_clear(c); mag_clear(r); arf_clear(t); } for (iter = 0; iter < 10000; iter++) { arb_t a, b, c; arf_t t; long e; arb_init(a); arb_init(b); arb_init(c); arf_init(t); arb_randtest_special(a, state, 1 + n_randint(state, 2000), 10); arb_randtest_special(b, state, 1 + n_randint(state, 2000), 10); e = n_randint(state, 10) - 10; /* c = a plus error bounds */ arb_set(c, a); arb_add_error_2exp_si(c, e); /* b = a + random point */ arb_set(b, a); arf_one(t); arf_mul_2exp_si(t, t, e); if (n_randint(state, 2)) arf_add(arb_midref(b), arb_midref(b), t, ARF_PREC_EXACT, ARF_RND_DOWN); else arf_sub(arb_midref(b), arb_midref(b), t, ARF_PREC_EXACT, ARF_RND_DOWN); /* should this be done differently? */ if (arf_is_nan(arb_midref(b))) arf_zero(arb_midref(b)); if (!arb_contains(c, b)) { printf("FAIL (arb_add_error_2exp_si)\n\n"); printf("a = "); arb_printn(a, 50, 0); printf("\n\n"); printf("b = "); arb_printn(b, 50, 0); printf("\n\n"); printf("c = "); arb_printn(c, 50, 0); printf("\n\n"); abort(); } arb_clear(a); arb_clear(b); arb_clear(c); arf_clear(t); } for (iter = 0; iter < 10000; iter++) { arb_t a, b, c; arf_t t; fmpz_t e; arb_init(a); arb_init(b); arb_init(c); arf_init(t); fmpz_init(e); arb_randtest_special(a, state, 1 + n_randint(state, 2000), 10); arb_randtest_special(b, state, 1 + n_randint(state, 2000), 10); fmpz_randtest(e, state, 10); /* c = a plus error bounds */ arb_set(c, a); arb_add_error_2exp_fmpz(c, e); /* b = a + random point */ arb_set(b, a); arf_one(t); arf_mul_2exp_fmpz(t, t, e); if (n_randint(state, 2)) arf_add(arb_midref(b), arb_midref(b), t, ARF_PREC_EXACT, ARF_RND_DOWN); else arf_sub(arb_midref(b), arb_midref(b), t, ARF_PREC_EXACT, ARF_RND_DOWN); /* should this be done differently? */ if (arf_is_nan(arb_midref(b))) arf_zero(arb_midref(b)); if (!arb_contains(c, b)) { printf("FAIL (arb_add_error_2exp_fmpz)\n\n"); printf("a = "); arb_printn(a, 50, 0); printf("\n\n"); printf("b = "); arb_printn(b, 50, 0); printf("\n\n"); printf("c = "); arb_printn(c, 50, 0); printf("\n\n"); abort(); } arb_clear(a); arb_clear(b); arb_clear(c); arf_clear(t); fmpz_clear(e); } flint_randclear(state); flint_cleanup(); printf("PASS\n"); return EXIT_SUCCESS; }
void arb_exp_arf_bb(arb_t z, const arf_t x, slong prec, int minus_one) { slong k, iter, bits, r, mag, q, wp, N; slong argred_bits, start_bits; mp_bitcnt_t Qexp[1]; int inexact; fmpz_t t, u, T, Q; arb_t w; if (arf_is_zero(x)) { if (minus_one) arb_zero(z); else arb_one(z); return; } if (arf_is_special(x)) { abort(); } mag = arf_abs_bound_lt_2exp_si(x); /* We assume that this function only gets called with something reasonable as input (huge/tiny input will be handled by the main exp wrapper). */ if (mag > 200 || mag < -2 * prec - 100) { flint_printf("arb_exp_arf_bb: unexpectedly large/small input\n"); abort(); } if (prec < 100000000) { argred_bits = 16; start_bits = 32; } else { argred_bits = 32; start_bits = 64; } /* Argument reduction: exp(x) -> exp(x/2^q). This improves efficiency of the first iteration in the bit-burst algorithm. */ q = FLINT_MAX(0, mag + argred_bits); /* Determine working precision. */ wp = prec + 10 + 2 * q + 2 * FLINT_BIT_COUNT(prec); if (minus_one && mag < 0) wp += (-mag); fmpz_init(t); fmpz_init(u); fmpz_init(Q); fmpz_init(T); arb_init(w); /* Convert x/2^q to a fixed-point number. */ inexact = arf_get_fmpz_fixed_si(t, x, -wp + q); /* Aliasing of z and x is safe now that only use t. */ /* Start with z = 1. */ arb_one(z); /* Bit-burst loop. */ for (iter = 0, bits = start_bits; !fmpz_is_zero(t); iter++, bits *= 2) { /* Extract bits. */ r = FLINT_MIN(bits, wp); fmpz_tdiv_q_2exp(u, t, wp - r); /* Binary splitting (+1 fixed-point ulp truncation error). */ mag = fmpz_bits(u) - r; N = bs_num_terms(mag, wp); _arb_exp_sum_bs_powtab(T, Q, Qexp, u, r, N); /* T = T / Q (+1 fixed-point ulp error). */ if (*Qexp >= wp) { fmpz_tdiv_q_2exp(T, T, *Qexp - wp); fmpz_tdiv_q(T, T, Q); } else { fmpz_mul_2exp(T, T, wp - *Qexp); fmpz_tdiv_q(T, T, Q); } /* T = 1 + T */ fmpz_one(Q); fmpz_mul_2exp(Q, Q, wp); fmpz_add(T, T, Q); /* Now T = exp(u) with at most 2 fixed-point ulp error. */ /* Set z = z * T. */ arf_set_fmpz(arb_midref(w), T); arf_mul_2exp_si(arb_midref(w), arb_midref(w), -wp); mag_set_ui_2exp_si(arb_radref(w), 2, -wp); arb_mul(z, z, w, wp); /* Remove used bits. */ fmpz_mul_2exp(u, u, wp - r); fmpz_sub(t, t, u); } /* We have exp(x + eps) - exp(x) < 2*eps (by assumption that the argument reduction is large enough). */ if (inexact) arb_add_error_2exp_si(z, -wp + 1); fmpz_clear(t); fmpz_clear(u); fmpz_clear(Q); fmpz_clear(T); arb_clear(w); /* exp(x) = exp(x/2^q)^(2^q) */ for (k = 0; k < q; k++) arb_mul(z, z, z, wp); if (minus_one) arb_sub_ui(z, z, 1, wp); arb_set_round(z, z, prec); }