int
fmprb_mat_lu(long * P, fmprb_mat_t LU, const fmprb_mat_t A, long prec)
{
fmprb_t d, e;
fmprb_ptr * a;
long i, j, m, n, r, row, col;
int result;
m = fmprb_mat_nrows(A);
n = fmprb_mat_ncols(A);
result = 1;
if (m == 0 || n == 0)
return result;
fmprb_mat_set(LU, A);
a = LU->rows;
row = col = 0;
for (i = 0; i < m; i++)
P[i] = i;
fmprb_init(d);
fmprb_init(e);
while (row < m && col < n)
{
r = fmprb_mat_find_pivot_partial(LU, row, m, col);
if (r == -1)
{
result = 0;
break;
}
else if (r != row)
fmprb_mat_swap_rows(LU, P, row, r);
fmprb_set(d, a[row] + col);
for (j = row + 1; j < m; j++)
{
fmprb_div(e, a[j] + col, d, prec);
fmprb_neg(e, e);
_fmprb_vec_scalar_addmul(a[j] + col,
a[row] + col, n - col, e, prec);
fmprb_zero(a[j] + col);
fmprb_neg(a[j] + row, e);
}
row++;
col++;
}
fmprb_clear(d);
fmprb_clear(e);
return result;
}
void
_fmprb_poly_product_roots(fmprb_ptr poly, fmprb_srcptr xs, long n, long prec)
{
if (n == 0)
{
fmprb_one(poly);
}
else if (n == 1)
{
fmprb_neg(poly, xs);
fmprb_one(poly + 1);
}
else if (n == 2)
{
fmprb_mul(poly, xs + 0, xs + 1, prec);
fmprb_add(poly + 1, xs + 0, xs + 1, prec);
fmprb_neg(poly + 1, poly + 1);
fmprb_one(poly + 2);
}
else
{
const long m = (n + 1) / 2;
fmprb_ptr tmp;
tmp = _fmprb_vec_init(n + 2);
_fmprb_poly_product_roots(tmp, xs, m, prec);
_fmprb_poly_product_roots(tmp + m + 1, xs + m, n - m, prec);
_fmprb_poly_mul_monic(poly, tmp, m + 1, tmp + m + 1, n - m + 1, prec);
_fmprb_vec_clear(tmp, n + 2);
}
}
void
fmprb_tanh(fmprb_t y, const fmprb_t x, long prec)
{
fmprb_t t, u;
fmprb_init(t);
fmprb_init(u);
fmprb_mul_2exp_si(t, x, 1);
if (fmpr_sgn(fmprb_midref(x)) >= 0)
{
fmprb_neg(t, t);
fmprb_expm1(t, t, prec + 4);
fmprb_add_ui(y, t, 2, prec + 4);
fmprb_div(y, t, y, prec);
fmprb_neg(y, y);
}
else
{
fmprb_expm1(t, t, prec + 4);
fmprb_add_ui(y, t, 2, prec + 4);
fmprb_div(y, t, y, prec);
}
fmprb_clear(t);
fmprb_clear(u);
}
void
fmpcb_cos_pi(fmpcb_t r, const fmpcb_t z, long prec)
{
#define a fmpcb_realref(z)
#define b fmpcb_imagref(z)
fmprb_t sa, ca, sb, cb;
fmprb_init(sa);
fmprb_init(ca);
fmprb_init(sb);
fmprb_init(cb);
fmprb_sin_cos_pi(sa, ca, a, prec);
fmprb_const_pi(cb, prec);
fmprb_mul(cb, cb, b, prec);
fmprb_sinh_cosh(sb, cb, cb, prec);
fmprb_mul(fmpcb_realref(r), ca, cb, prec);
fmprb_mul(fmpcb_imagref(r), sa, sb, prec);
fmprb_neg(fmpcb_imagref(r), fmpcb_imagref(r));
fmprb_clear(sa);
fmprb_clear(ca);
fmprb_clear(sb);
fmprb_clear(cb);
#undef a
#undef b
}
void
fmprb_hypgeom_infsum(fmprb_t P, fmprb_t Q, hypgeom_t hyp, long target_prec, long prec)
{
mag_t err, z;
long n;
mag_init(err);
mag_init(z);
mag_set_fmpz(z, hyp->P->coeffs + hyp->P->length - 1);
mag_div_fmpz(z, z, hyp->Q->coeffs + hyp->Q->length - 1);
if (!hyp->have_precomputed)
{
hypgeom_precompute(hyp);
hyp->have_precomputed = 1;
}
n = hypgeom_bound(err, hyp->r, hyp->boundC, hyp->boundD,
hyp->boundK, hyp->MK, z, target_prec);
fmprb_hypgeom_sum(P, Q, hyp, n, prec);
if (fmpr_sgn(fmprb_midref(Q)) < 0)
{
fmprb_neg(P, P);
fmprb_neg(Q, Q);
}
/* We have p/q = s + err i.e. (p + q*err)/q = s */
{
fmpr_t u, v;
fmpr_init(u);
fmpr_init(v);
mag_get_fmpr(v, err);
fmpr_add(u, fmprb_midref(Q), fmprb_radref(Q), FMPRB_RAD_PREC, FMPR_RND_UP);
fmpr_mul(u, u, v, FMPRB_RAD_PREC, FMPR_RND_UP);
fmprb_add_error_fmpr(P, u);
fmpr_clear(u);
fmpr_clear(v);
}
mag_clear(z);
mag_clear(err);
}
long
fmprb_mat_gauss_partial(fmprb_mat_t A, long prec)
{
fmprb_t e;
fmprb_ptr * a;
long j, m, n, r, rank, row, col, sign;
m = A->r;
n = A->c;
a = A->rows;
rank = row = col = 0;
sign = 1;
fmprb_init(e);
while (row < m && col < n)
{
r = fmprb_mat_find_pivot_partial(A, row, m, col);
if (r == -1)
{
break;
}
else if (r != row)
{
fmprb_mat_swap_rows(A, NULL, row, r);
sign *= -1;
}
rank++;
for (j = row + 1; j < m; j++)
{
fmprb_div(e, a[j] + col, a[row] + col, prec);
fmprb_neg(e, e);
_fmprb_vec_scalar_addmul(a[j] + col + 1, a[row] + col + 1, n - col - 1, e, prec);
}
row++;
col++;
}
fmprb_clear(e);
return rank * sign;
}
void
_fmprb_poly_riemann_siegel_theta_series(fmprb_ptr res,
fmprb_srcptr h, long hlen, long len, long prec)
{
fmpcb_ptr s;
fmprb_t u;
long i;
hlen = FLINT_MIN(hlen, len);
s = _fmpcb_vec_init(len);
fmprb_init(u);
/* s = 1/4 + (1/2) i h */
for (i = 0; i < hlen; i++)
fmprb_mul_2exp_si(fmpcb_imagref(s + i), h + i, -1);
fmprb_one(u);
fmprb_mul_2exp_si(u, u, -2);
fmprb_add(fmpcb_realref(s), fmpcb_realref(s), u, prec);
/* log gamma */
_fmpcb_poly_lgamma_series(s, s, hlen, len, prec);
/* imaginary part */
for (i = 0; i < len; i++)
fmprb_set(res + i, fmpcb_imagref(s + i));
/* subtract log(pi)/2 * h */
fmprb_const_pi(u, prec);
fmprb_log(u, u, prec);
fmprb_mul_2exp_si(u, u, -1);
fmprb_neg(u, u);
_fmprb_vec_scalar_addmul(res, h, hlen, u, prec);
_fmpcb_vec_clear(s, len);
fmprb_clear(u);
}
void
gamma_stirling_eval_fmprb(fmprb_t s, const fmprb_t z, long nterms, int digamma, long prec)
{
fmprb_t b, t, logz, zinv, zinv2;
fmpr_t err;
long k, term_prec;
double z_mag, term_mag;
fmprb_init(b);
fmprb_init(t);
fmprb_init(logz);
fmprb_init(zinv);
fmprb_init(zinv2);
fmprb_log(logz, z, prec);
fmprb_ui_div(zinv, 1UL, z, prec);
nterms = FLINT_MAX(nterms, 1);
fmprb_zero(s);
if (nterms > 1)
{
fmprb_mul(zinv2, zinv, zinv, prec);
z_mag = fmpr_get_d(fmprb_midref(logz), FMPR_RND_UP) * 1.44269504088896;
for (k = nterms - 1; k >= 1; k--)
{
term_mag = bernoulli_bound_2exp_si(2 * k);
term_mag -= (2 * k - 1) * z_mag;
term_prec = prec + term_mag;
term_prec = FLINT_MIN(term_prec, prec);
term_prec = FLINT_MAX(term_prec, 10);
if (prec > 2000)
{
fmprb_set_round(t, zinv2, term_prec);
fmprb_mul(s, s, t, term_prec);
}
else
fmprb_mul(s, s, zinv2, term_prec);
gamma_stirling_coeff(b, k, digamma, term_prec);
fmprb_add(s, s, b, term_prec);
}
if (digamma)
fmprb_mul(s, s, zinv2, prec);
else
fmprb_mul(s, s, zinv, prec);
}
/* remainder bound */
fmpr_init(err);
gamma_stirling_bound_fmprb(err, z, digamma ? 1 : 0, 1, nterms);
fmprb_add_error_fmpr(s, err);
fmpr_clear(err);
if (digamma)
{
fmprb_neg(s, s);
fmprb_mul_2exp_si(zinv, zinv, -1);
fmprb_sub(s, s, zinv, prec);
fmprb_add(s, s, logz, prec);
}
else
{
/* (z-0.5)*log(z) - z + log(2*pi)/2 */
fmprb_one(t);
fmprb_mul_2exp_si(t, t, -1);
fmprb_sub(t, z, t, prec);
fmprb_mul(t, logz, t, prec);
fmprb_add(s, s, t, prec);
fmprb_sub(s, s, z, prec);
fmprb_const_log_sqrt2pi(t, prec);
fmprb_add(s, s, t, prec);
}
fmprb_clear(t);
fmprb_clear(b);
fmprb_clear(zinv);
fmprb_clear(zinv2);
fmprb_clear(logz);
}
void
_fmprb_poly_zeta_series(fmprb_ptr res, fmprb_srcptr h, long hlen, const fmprb_t a, int deflate, long len, long prec)
{
long i;
fmpcb_t cs, ca;
fmpcb_ptr z;
fmprb_ptr t, u;
if (fmprb_contains_nonpositive(a))
{
_fmprb_vec_indeterminate(res, len);
return;
}
hlen = FLINT_MIN(hlen, len);
z = _fmpcb_vec_init(len);
t = _fmprb_vec_init(len);
u = _fmprb_vec_init(len);
fmpcb_init(cs);
fmpcb_init(ca);
/* use reflection formula */
if (fmpr_sgn(fmprb_midref(h)) < 0 && fmprb_is_one(a))
{
/* zeta(s) = (2*pi)**s * sin(pi*s/2) / pi * gamma(1-s) * zeta(1-s) */
fmprb_t pi;
fmprb_ptr f, s1, s2, s3, s4;
fmprb_init(pi);
f = _fmprb_vec_init(2);
s1 = _fmprb_vec_init(len);
s2 = _fmprb_vec_init(len);
s3 = _fmprb_vec_init(len);
s4 = _fmprb_vec_init(len);
fmprb_const_pi(pi, prec);
/* s1 = (2*pi)**s */
fmprb_mul_2exp_si(pi, pi, 1);
_fmprb_poly_pow_cpx(s1, pi, h, len, prec);
fmprb_mul_2exp_si(pi, pi, -1);
/* s2 = sin(pi*s/2) / pi */
fmprb_mul_2exp_si(pi, pi, -1);
fmprb_mul(f, pi, h, prec);
fmprb_set(f + 1, pi);
fmprb_mul_2exp_si(pi, pi, 1);
_fmprb_poly_sin_series(s2, f, 2, len, prec);
_fmprb_vec_scalar_div(s2, s2, len, pi, prec);
/* s3 = gamma(1-s) */
fmprb_sub_ui(f, h, 1, prec);
fmprb_neg(f, f);
fmprb_set_si(f + 1, -1);
_fmprb_poly_gamma_series(s3, f, 2, len, prec);
/* s4 = zeta(1-s) */
fmprb_sub_ui(f, h, 1, prec);
fmprb_neg(f, f);
fmpcb_set_fmprb(cs, f);
fmpcb_one(ca);
zeta_series(z, cs, ca, 0, len, prec);
for (i = 0; i < len; i++)
fmprb_set(s4 + i, fmpcb_realref(z + i));
for (i = 1; i < len; i += 2)
fmprb_neg(s4 + i, s4 + i);
_fmprb_poly_mullow(u, s1, len, s2, len, len, prec);
_fmprb_poly_mullow(s1, s3, len, s4, len, len, prec);
_fmprb_poly_mullow(t, u, len, s1, len, len, prec);
/* add 1/(1-(s+t)) = 1/(1-s) + t/(1-s)^2 + ... */
if (deflate)
{
fmprb_sub_ui(u, h, 1, prec);
fmprb_neg(u, u);
fmprb_ui_div(u, 1, u, prec);
for (i = 1; i < len; i++)
fmprb_mul(u + i, u + i - 1, u, prec);
_fmprb_vec_add(t, t, u, len, prec);
}
fmprb_clear(pi);
_fmprb_vec_clear(f, 2);
_fmprb_vec_clear(s1, len);
_fmprb_vec_clear(s2, len);
_fmprb_vec_clear(s3, len);
_fmprb_vec_clear(s4, len);
}
else
{
fmpcb_set_fmprb(cs, h);
fmpcb_set_fmprb(ca, a);
zeta_series(z, cs, ca, deflate, len, prec);
for (i = 0; i < len; i++)
fmprb_set(t + i, fmpcb_realref(z + i));
}
/* compose with nonconstant part */
fmprb_zero(u);
_fmprb_vec_set(u + 1, h + 1, hlen - 1);
_fmprb_poly_compose_series(res, t, len, u, hlen, len, prec);
_fmpcb_vec_clear(z, len);
_fmprb_vec_clear(t, len);
_fmprb_vec_clear(u, len);
fmpcb_init(cs);
fmpcb_init(ca);
}
void
_fmprb_poly_evaluate_vec_fast_precomp(fmprb_ptr vs, fmprb_srcptr poly,
long plen, fmprb_ptr * tree, long len, long prec)
{
long height, i, j, pow, left;
long tree_height;
long tlen;
fmprb_ptr t, u, swap, pa, pb, pc;
/* avoid worrying about some degenerate cases */
if (len < 2 || plen < 2)
{
if (len == 1)
{
fmprb_t tmp;
fmprb_init(tmp);
fmprb_neg(tmp, tree[0] + 0);
_fmprb_poly_evaluate(vs + 0, poly, plen, tmp, prec);
fmprb_clear(tmp);
}
else if (len != 0 && plen == 0)
{
_fmprb_vec_zero(vs, len);
}
else if (len != 0 && plen == 1)
{
for (i = 0; i < len; i++)
fmprb_set(vs + i, poly + 0);
}
return;
}
t = _fmprb_vec_init(len);
u = _fmprb_vec_init(len);
left = len;
/* Initial reduction. We allow the polynomial to be larger
or smaller than the number of points. */
height = FLINT_BIT_COUNT(plen - 1) - 1;
tree_height = FLINT_CLOG2(len);
while (height >= tree_height)
height--;
pow = 1L << height;
for (i = j = 0; i < len; i += pow, j += (pow + 1))
{
tlen = ((i + pow) <= len) ? pow : len % pow;
_fmprb_poly_rem(t + i, poly, plen, tree[height] + j, tlen + 1, prec);
}
for (i = height - 1; i >= 0; i--)
{
pow = 1L << i;
left = len;
pa = tree[i];
pb = t;
pc = u;
while (left >= 2 * pow)
{
_fmprb_poly_rem_2(pc, pb, 2 * pow, pa, pow + 1, prec);
_fmprb_poly_rem_2(pc + pow, pb, 2 * pow, pa + pow + 1, pow + 1, prec);
pa += 2 * pow + 2;
pb += 2 * pow;
pc += 2 * pow;
left -= 2 * pow;
}
if (left > pow)
{
_fmprb_poly_rem(pc, pb, left, pa, pow + 1, prec);
_fmprb_poly_rem(pc + pow, pb, left, pa + pow + 1, left - pow + 1, prec);
}
else if (left > 0)
_fmprb_vec_set(pc, pb, left);
swap = t;
t = u;
u = swap;
}
_fmprb_vec_set(vs, t, len);
_fmprb_vec_clear(t, len);
_fmprb_vec_clear(u, len);
}
static void
_fmprb_gamma(fmprb_t y, const fmprb_t x, long prec, int inverse)
{
int reflect;
long r, n, wp;
fmprb_t t, u, v;
if (fmprb_is_exact(x))
{
const fmpr_struct * mid = fmprb_midref(x);
if (fmpr_is_special(mid))
{
if (!inverse && fmpr_is_pos_inf(mid))
{
fmprb_set(y, x);
}
else if (fmpr_is_nan(mid) || fmpr_is_neg_inf(mid) || !inverse)
{
fmpr_nan(fmprb_midref(y));
fmpr_pos_inf(fmprb_radref(y));
}
else
{
fmprb_zero(y);
}
return;
}
else
{
const fmpz exp = *fmpr_expref(mid);
const fmpz man = *fmpr_manref(mid);
/* fast gamma(n), gamma(n/2) or gamma(n/4) */
if (!COEFF_IS_MPZ(exp) && (exp >= -2) &&
((double) fmpz_bits(&man) + exp < prec))
{
fmpq_t a;
fmpq_init(a);
fmpr_get_fmpq(a, mid);
fmprb_gamma_fmpq(y, a, prec + 2 * inverse);
if (inverse)
fmprb_ui_div(y, 1, y, prec);
fmpq_clear(a);
return;
}
}
}
wp = prec + FLINT_BIT_COUNT(prec);
gamma_stirling_choose_param_fmprb(&reflect, &r, &n, x, 1, 0, wp);
fmprb_init(t);
fmprb_init(u);
fmprb_init(v);
if (reflect)
{
/* gamma(x) = (rf(1-x, r) * pi) / (gamma(1-x+r) sin(pi x)) */
fmprb_sub_ui(t, x, 1, wp);
fmprb_neg(t, t);
gamma_rising_fmprb_ui_bsplit(u, t, r, wp);
fmprb_const_pi(v, wp);
fmprb_mul(u, u, v, wp);
fmprb_add_ui(t, t, r, wp);
gamma_stirling_eval_fmprb(v, t, n, 0, wp);
fmprb_exp(v, v, wp);
fmprb_sin_pi(t, x, wp);
fmprb_mul(v, v, t, wp);
}
else
{
/* gamma(x) = gamma(x+r) / rf(x,r) */
fmprb_add_ui(t, x, r, wp);
gamma_stirling_eval_fmprb(u, t, n, 0, wp);
fmprb_exp(u, u, prec);
gamma_rising_fmprb_ui_bsplit(v, x, r, wp);
}
if (inverse)
fmprb_div(y, v, u, prec);
else
fmprb_div(y, u, v, prec);
fmprb_clear(t);
fmprb_clear(u);
fmprb_clear(v);
}
void
_fmprb_poly_rgamma_series(fmprb_ptr res, fmprb_srcptr h, long hlen, long len, long prec)
{
int reflect;
long i, rflen, r, n, wp;
fmprb_ptr t, u, v;
fmprb_struct f[2];
hlen = FLINT_MIN(hlen, len);
wp = prec + FLINT_BIT_COUNT(prec);
t = _fmprb_vec_init(len);
u = _fmprb_vec_init(len);
v = _fmprb_vec_init(len);
fmprb_init(f);
fmprb_init(f + 1);
/* use zeta values at small integers */
if (fmprb_is_int(h) && (fmpr_cmpabs_ui(fmprb_midref(h), prec / 2) < 0))
{
r = fmpr_get_si(fmprb_midref(h), FMPR_RND_DOWN);
gamma_lgamma_series_at_one(u, len, wp);
_fmprb_vec_neg(u, u, len);
_fmprb_poly_exp_series(t, u, len, len, wp);
if (r == 1)
{
_fmprb_vec_swap(v, t, len);
}
else if (r <= 0)
{
fmprb_set(f, h);
fmprb_one(f + 1);
rflen = FLINT_MIN(len, 2 - r);
_fmprb_poly_rising_ui_series(u, f, FLINT_MIN(2, len), 1 - r, rflen, wp);
_fmprb_poly_mullow(v, t, len, u, rflen, len, wp);
}
else
{
fmprb_one(f);
fmprb_one(f + 1);
rflen = FLINT_MIN(len, r);
_fmprb_poly_rising_ui_series(v, f, FLINT_MIN(2, len), r - 1, rflen, wp);
/* TODO: use div_series? */
_fmprb_poly_inv_series(u, v, rflen, len, wp);
_fmprb_poly_mullow(v, t, len, u, len, len, wp);
}
}
else
{
/* otherwise use Stirling series */
gamma_stirling_choose_param_fmprb(&reflect, &r, &n, h, 1, 0, wp);
/* rgamma(h) = (gamma(1-h+r) sin(pi h)) / (rf(1-h, r) * pi), h = h0 + t*/
if (reflect)
{
/* u = gamma(r+1-h) */
fmprb_sub_ui(f, h, r + 1, wp);
fmprb_neg(f, f);
gamma_stirling_eval_fmprb_series(t, f, n, len, wp);
_fmprb_poly_exp_series(u, t, len, len, wp);
for (i = 1; i < len; i += 2)
fmprb_neg(u + i, u + i);
/* v = sin(pi x) */
fmprb_const_pi(f + 1, wp);
fmprb_mul(f, h, f + 1, wp);
_fmprb_poly_sin_series(v, f, 2, len, wp);
_fmprb_poly_mullow(t, u, len, v, len, len, wp);
/* rf(1-h,r) * pi */
if (r == 0)
{
fmprb_const_pi(u, wp);
_fmprb_vec_scalar_div(v, t, len, u, wp);
}
else
{
fmprb_sub_ui(f, h, 1, wp);
fmprb_neg(f, f);
fmprb_set_si(f + 1, -1);
rflen = FLINT_MIN(len, r + 1);
_fmprb_poly_rising_ui_series(v, f, FLINT_MIN(2, len), r, rflen, wp);
fmprb_const_pi(u, wp);
_fmprb_vec_scalar_mul(v, v, rflen, u, wp);
/* divide by rising factorial */
/* TODO: might better to use div_series, when it has a good basecase */
_fmprb_poly_inv_series(u, v, rflen, len, wp);
_fmprb_poly_mullow(v, t, len, u, len, len, wp);
}
}
else
{
/* rgamma(h) = rgamma(h+r) rf(h,r) */
if (r == 0)
{
fmprb_add_ui(f, h, r, wp);
gamma_stirling_eval_fmprb_series(t, f, n, len, wp);
_fmprb_vec_neg(t, t, len);
_fmprb_poly_exp_series(v, t, len, len, wp);
}
else
{
fmprb_set(f, h);
fmprb_one(f + 1);
rflen = FLINT_MIN(len, r + 1);
_fmprb_poly_rising_ui_series(t, f, FLINT_MIN(2, len), r, rflen, wp);
fmprb_add_ui(f, h, r, wp);
gamma_stirling_eval_fmprb_series(v, f, n, len, wp);
_fmprb_vec_neg(v, v, len);
_fmprb_poly_exp_series(u, v, len, len, wp);
_fmprb_poly_mullow(v, u, len, t, rflen, len, wp);
}
}
}
/* compose with nonconstant part */
fmprb_zero(t);
_fmprb_vec_set(t + 1, h + 1, hlen - 1);
_fmprb_poly_compose_series(res, v, len, t, hlen, len, prec);
fmprb_clear(f);
fmprb_clear(f + 1);
_fmprb_vec_clear(t, len);
_fmprb_vec_clear(u, len);
_fmprb_vec_clear(v, len);
}
