Merge branch 'master' of github.com:fredrik-johansson/arb

This commit is contained in:
fredrik 2019-08-13 16:24:26 +02:00
commit 7fa6176f4e
10 changed files with 1510 additions and 24 deletions

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@ -252,7 +252,7 @@ void acb_dirichlet_platt_ws_precomp_init(acb_dirichlet_platt_ws_precomp_t pre,
slong A, const arb_t H, slong sigma, slong prec);
void acb_dirichlet_platt_ws_precomp_clear(acb_dirichlet_platt_ws_precomp_t pre);
void acb_dirichlet_platt_ws_interpolation_precomp(arb_t res,
acb_dirichlet_platt_ws_precomp_t pre, const arb_t t0,
const acb_dirichlet_platt_ws_precomp_t pre, const arb_t t0,
arb_srcptr p, const fmpz_t T, slong A, slong B, slong Ns_max,
const arb_t H, slong sigma, slong prec);
void acb_dirichlet_platt_ws_interpolation(arb_t res, const arb_t t0,
@ -288,6 +288,12 @@ void acb_dirichlet_platt_lemma_B2(arb_t out, slong K, const arb_t h,
void acb_dirichlet_platt_multieval(arb_ptr out, const fmpz_t T, slong A,
slong B, const arb_t h, slong J, slong K, slong sigma, slong prec);
slong _acb_dirichlet_platt_local_hardy_z_zeros(
arb_ptr res, const fmpz_t n, slong len,
const fmpz_t T, slong A, slong B,
const arb_t h, slong J, slong K, slong sigma_grid,
slong Ns_max, const arb_t H, slong sigma_interp, slong prec);
/* Discrete Fourier Transform */
void acb_dirichlet_dft_index(acb_ptr w, acb_srcptr v, const dirichlet_group_t G, slong prec);

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@ -1093,8 +1093,8 @@ _isolate_hardy_z_zeros(arf_interval_ptr res, const fmpz_t n, slong len)
}
/* Isolate len zeros, starting from the nth zero. */
static void
isolate_hardy_z_zeros(arf_interval_ptr res, const fmpz_t n, slong len)
void
acb_dirichlet_isolate_hardy_z_zeros(arf_interval_ptr res, const fmpz_t n, slong len)
{
if (len <= 0)
{
@ -1392,7 +1392,7 @@ acb_dirichlet_hardy_z_zeros(arb_ptr res, const fmpz_t n, slong len, slong prec)
{
slong i;
arf_interval_ptr p = _arf_interval_vec_init(len);
isolate_hardy_z_zeros(p, n, len);
acb_dirichlet_isolate_hardy_z_zeros(p, n, len);
for (i = 0; i < len; i++)
{
_acb_dirichlet_refine_hardy_z_zero(res + i, &p[i].a, &p[i].b, prec);

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@ -28,7 +28,7 @@ _gamma_upper_workaround(arb_t res, const arb_t s, const arb_t z,
arb_init(x);
for (i = 0; i < 5; i++)
{
arb_hypgeom_gamma_upper(x, s, z, regularized, prec * (1 << i));
arb_hypgeom_gamma_upper(x, s, z, regularized, prec << i);
if (arb_rel_accuracy_bits(x) > 1)
{
break;

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@ -28,7 +28,7 @@ _gamma_upper_workaround(arb_t res, const arb_t s, const arb_t z,
arb_init(x);
for (i = 0; i < 5; i++)
{
arb_hypgeom_gamma_upper(x, s, z, regularized, prec * (1 << i));
arb_hypgeom_gamma_upper(x, s, z, regularized, prec << i);
if (arb_rel_accuracy_bits(x) > 1)
{
break;

View file

@ -29,7 +29,7 @@ _gamma_upper_workaround(arb_t res, const arb_t s, const arb_t z,
arb_init(x);
for (i = 0; i < 5; i++)
{
arb_hypgeom_gamma_upper(x, s, z, regularized, prec * (1 << i));
arb_hypgeom_gamma_upper(x, s, z, regularized, prec << i);
if (arb_rel_accuracy_bits(x) > 1)
{
break;

File diff suppressed because it is too large Load diff

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@ -28,7 +28,7 @@ _gamma_upper_workaround(arb_t res, const arb_t s, const arb_t z,
arb_init(x);
for (i = 0; i < 5; i++)
{
arb_hypgeom_gamma_upper(x, s, z, regularized, prec * (1 << i));
arb_hypgeom_gamma_upper(x, s, z, regularized, prec << i);
if (arb_rel_accuracy_bits(x) > 1)
{
break;
@ -77,7 +77,9 @@ _arb_gaussian(arb_t res, const arb_t a, const arb_t b, const arb_t c,
arb_mul_2exp_si(z, z, -1);
arb_neg(z, z);
arb_exp(z, z, prec);
if (a != NULL)
if (a == NULL)
arb_set(res, z);
else
arb_mul(res, z, a, prec);
arb_clear(z);
}
@ -339,41 +341,89 @@ _interpolation_helper(arb_t res, const acb_dirichlet_platt_ws_precomp_t pre,
const arb_t t0, arb_srcptr p, const fmpz_t T, slong A, slong B,
slong i0, slong Ns, const arb_t H, slong sigma, slong prec)
{
arb_t dt0, dt, a, s, err, total;
mag_t m;
arb_t accum1; /* sum of terms where the argument of sinc is small */
arb_t accum2; /* sum of terms where the argument of sinc is large */
arb_t total, dt0, dt, a, b, s, err, pi, g, x, c;
slong i;
slong N = A*B;
mag_init(m);
arb_init(accum1);
arb_init(accum2);
arb_init(total);
arb_init(dt0);
arb_init(dt);
arb_init(a);
arb_init(b);
arb_init(s);
arb_init(err);
arb_init(total);
arb_init(pi);
arb_init(g);
arb_init(x);
arb_init(c);
arb_const_pi(pi, prec);
arb_sub_fmpz(dt0, t0, T, prec + fmpz_clog_ui(T, 2));
/* x = -N/2 - A*dt0 */
arb_mul_si(x, dt0, A, prec);
arb_add_si(x, x, N/2, prec);
arb_neg(x, x);
/* c = sin(pi*x) / pi */
arb_sin_pi(c, x, prec);
arb_div(c, c, pi, prec);
for (i = i0; i < i0 + 2*Ns; i++)
{
slong n = i - N/2;
_arb_div_si_si(dt, n, A, prec);
arb_sub(a, dt, dt0, prec);
arb_mul_si(a, a, A, prec);
arb_sinc_pi(a, a, prec);
arb_mul(a, a, p + i, prec);
_arb_gaussian(s, a, dt0, H, dt, prec);
arb_add(total, total, s, prec);
_arb_gaussian(g, NULL, dt0, H, dt, prec);
arb_mul(s, g, p + i, prec);
arb_add_si(a, x, i, prec);
arb_get_mag(m, a);
if (mag_cmp_2exp_si(m, -1) < 0)
{
arb_sinc_pi(b, a, prec);
arb_addmul(accum1, s, b, prec);
}
else
{
arb_div(b, s, a, prec);
if (i % 2)
{
arb_neg(b, b);
}
arb_add(accum2, accum2, b, prec);
}
}
arb_set(total, accum1);
arb_addmul(total, accum2, c, prec);
acb_dirichlet_platt_bound_C3(err, t0, A, H, Ns, prec);
arb_add_error(total, err);
acb_dirichlet_platt_i_bound_precomp(
err, &pre->pre_i, &pre->pre_c, t0, A, H, sigma, prec);
arb_add_error(total, err);
arb_set(res, total);
mag_clear(m);
arb_clear(accum1);
arb_clear(accum2);
arb_clear(total);
arb_clear(dt0);
arb_clear(dt);
arb_clear(a);
arb_clear(b);
arb_clear(s);
arb_clear(err);
arb_clear(total);
arb_clear(pi);
arb_clear(g);
arb_clear(x);
arb_clear(c);
}
void
acb_dirichlet_platt_ws_precomp_init(acb_dirichlet_platt_ws_precomp_t pre,
slong A, const arb_t H, slong sigma, slong prec)
@ -390,7 +440,7 @@ acb_dirichlet_platt_ws_precomp_clear(acb_dirichlet_platt_ws_precomp_t pre)
}
void acb_dirichlet_platt_ws_interpolation_precomp(arb_t res,
acb_dirichlet_platt_ws_precomp_t pre, const arb_t t0,
const acb_dirichlet_platt_ws_precomp_t pre, const arb_t t0,
arb_srcptr p, const fmpz_t T, slong A, slong B, slong Ns_max,
const arb_t H, slong sigma, slong prec)
{

View file

@ -0,0 +1,87 @@
/*
Copyright (C) 2019 D.H.J. Polymath
This file is part of Arb.
Arb is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version. See <http://www.gnu.org/licenses/>.
*/
#include "acb_dirichlet.h"
int main()
{
/* Check a specific combination of parameter values that is relatively fast
* to evaluate and that has relatively tight bounds. */
slong A, B, J, K, sigma_grid, Ns_max, sigma_interp;
arb_t h, H;
fmpz_t T, n;
arb_ptr pa, pb;
slong count, i;
slong maxcount = 50;
slong prec = 128;
flint_printf("platt_local_hardy_z_zeros....");
fflush(stdout);
arb_init(h);
arb_init(H);
fmpz_init(T);
fmpz_init(n);
pa = _arb_vec_init(maxcount);
pb = _arb_vec_init(maxcount);
fmpz_set_si(n, 10142);
/* parameters related to the location/resolution/width of the grid */
fmpz_set_si(T, 10000);
A = 8;
B = 128;
/* tuning parameters for the evaluation of grid points */
J = 1000;
K = 30;
sigma_grid = 63;
arb_set_d(h, 4.5);
/* tuning parameters for interpolation on the grid */
Ns_max = 200;
sigma_interp = 21;
arb_one(H);
count = _acb_dirichlet_platt_local_hardy_z_zeros(pa, n, maxcount,
T, A, B, h, J, K, sigma_grid, Ns_max, H, sigma_interp, prec);
acb_dirichlet_hardy_z_zeros(pb, n, count, prec);
if (count != maxcount)
{
flint_printf("FAIL: not enough zeros were isolated\n\n");
flint_printf("count = %wd maxcount = %wd\n\n", count, maxcount);
flint_abort();
}
for (i = 0; i < count; i++)
{
if (!arb_overlaps(pa+i, pb+i))
{
flint_printf("FAIL: overlap\n\n");
flint_printf("observed[%wd] = ", i);
arb_printd(pa+i, 20); flint_printf("\n\n");
flint_printf("expected[%wd] = ", i);
arb_printd(pb+i, 20); flint_printf("\n\n");
flint_abort();
}
}
arb_clear(h);
arb_clear(H);
fmpz_clear(T);
fmpz_clear(n);
_arb_vec_clear(pa, maxcount);
_arb_vec_clear(pb, maxcount);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}

View file

@ -11,6 +11,13 @@
#include "acb_dirichlet.h"
static void
_arb_inv_si(arb_t res, slong a, slong prec)
{
arb_set_si(res, a);
arb_inv(res, res, prec);
}
static void
_arb_div_si_si(arb_t res, slong a, slong b, slong prec)
{
@ -32,6 +39,26 @@ _arb_vec_overlaps(arb_srcptr a, arb_srcptr b, slong len)
return 1;
}
static void
_check_containment(const char *name, const arb_t x, const char *s)
{
arb_t u;
slong prec = 300;
arb_init(u);
arb_set_str(u, s, prec);
if (!arb_contains(u, x))
{
flint_printf("FAIL: %s\n\n", name);
flint_printf("observed = "); arb_printn(x, 30, 0); flint_printf("\n\n");
flint_printf("expected = "); arb_printn(u, 30, 0); flint_printf("\n\n");
flint_abort();
}
arb_clear(u);
}
int main()
{
slong iter;
@ -60,11 +87,69 @@ int main()
fmpz_set_si(T, 10000);
arb_set_d(h, 4.5);
/* Spot-check lemma bound containment
* in intervals calculated with PARI/GP. */
{
arb_t lem, xi, x, beta, t0;
slong i = 201;
slong k = 5;
slong wp = 300;
arb_init(lem);
arb_init(xi);
arb_init(x);
arb_init(t0);
arb_init(beta);
_arb_inv_si(xi, B, wp);
arb_mul_2exp_si(xi, xi, -1);
_arb_div_si_si(x, i, B, wp);
arb_set_fmpz(t0, T);
acb_dirichlet_platt_beta(beta, t0, wp);
acb_dirichlet_platt_lemma_32(lem, h, t0, x, wp);
_check_containment("Lemma 3.2", lem,
"[5.3526496753240991744e-1072334 +/- 2.55e-1072354]");
acb_dirichlet_platt_c_bound(lem, sigma, t0, h, k, wp);
_check_containment("Lemma A.3", lem,
"[1.3516642396389823078e+134 +/- 2.65e+114]");
acb_dirichlet_platt_lemma_A5(lem, B, h, k, wp);
_check_containment("Lemma A.5", lem,
"[1.0075390047893384632e-30 +/- 5.57e-51]");
acb_dirichlet_platt_lemma_A7(lem, sigma, t0, h, k, A, wp);
_check_containment("Lemma A.7", lem,
"[3.0406705491484062400e-505 +/- 1.57e-525]");
acb_dirichlet_platt_lemma_A9(lem, sigma, t0, h, A, wp);
_check_containment("Lemma A.9", lem,
"[6.8953211848420326275e-536 +/- 3.52e-556]");
acb_dirichlet_platt_lemma_A11(lem, t0, h, B, wp);
_check_containment("Lemma A.11", lem,
"[3.0825745863006335768e-42 +/- 3.68e-62]");
acb_dirichlet_platt_lemma_B1(lem, sigma, t0, h, J, wp);
_check_containment("Lemma B.1", lem,
"[8.5737638613320328274e-42 +/- 7.50e-63]");
acb_dirichlet_platt_lemma_B2(lem, K, h, xi, wp);
_check_containment("Lemma B.2", lem,
"[2.0748437544358592615e-44 +/- 4.76e-64]");
arb_clear(lem);
arb_clear(xi);
arb_clear(x);
arb_clear(t0);
arb_clear(beta);
}
/* Check a few random entries in the multieval vector. */
vec = _arb_vec_init(N);
acb_dirichlet_platt_multieval(vec, T, A, B, h, J, K, sigma, prec);
/* Check only a few random entries in the multieval vector. */
for (iter = 0; iter < 20; iter++)
{
arb_t t, r;
@ -78,8 +163,8 @@ int main()
if (!arb_overlaps(vec + i, r))
{
flint_printf("FAIL: overlap for hardcoded example\n\n");
flint_printf("n = %wd\n\n", n);
flint_printf("vec[i] = "); arb_printn(vec + i, 30, 0); flint_printf("\n\n");
flint_printf("i = %wd n = %wd\n\n", i, n);
flint_printf("vec[%wd] = ", i); arb_printn(vec + i, 30, 0); flint_printf("\n\n");
flint_printf("r = "); arb_printn(r, 30, 0); flint_printf("\n\n");
flint_abort();
}

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@ -777,3 +777,12 @@ and formulas described by David J. Platt in [Pla2017]_.
interpolation. *sigma* is an odd positive integer tuning parameter
`\sigma \in 2\mathbb{Z}_{>0}+1` used in computing error bounds.
.. function:: slong _acb_dirichlet_platt_local_hardy_z_zeros(arb_ptr res, const fmpz_t n, slong len, const fmpz_t T, slong A, slong B, const arb_t h, slong J, slong K, slong sigma_grid, slong Ns_max, const arb_t H, slong sigma_interp, slong prec)
Sets the entries of *res* to at most *len* consecutive zeros of the
Hardy Z-function, beginning with the *n*-th zero. The number of zeros
isolated near *T* is returned. Requires positive *n*.
Internally this function uses Platt's grid evaluation of the scaled
Lambda function, and the final several parameters have the same meanings
as in the functions :func:`acb_dirichlet_platt_multieval`
and :func:`acb_dirichlet_platt_ws_interpolation`.