void
arb_poly_div_series(arb_poly_t Q, const arb_poly_t A, const arb_poly_t B, long n, long prec)
{
if (n == 0 || B->length == 0)
{
printf("arb_poly_inv_series: require n > 0 and nonzero input\n");
abort();
}
if (A->length == 0)
{
arb_poly_zero(Q);
return;
}
if (Q == A || Q == B)
{
arb_poly_t t;
arb_poly_init(t);
arb_poly_div_series(t, A, B, n, prec);
arb_poly_swap(Q, t);
arb_poly_clear(t);
return;
}
arb_poly_fit_length(Q, n);
_arb_poly_div_series(Q->coeffs, A->coeffs, A->length, B->coeffs, B->length, n, prec);
_arb_poly_set_length(Q, n);
_arb_poly_normalise(Q);
}
void
arb_poly_div_series(arb_poly_t Q, const arb_poly_t A, const arb_poly_t B, long n, long prec)
{
if (n == 0)
{
arb_poly_zero(Q);
return;
}
if (B->length == 0)
{
arb_poly_fit_length(Q, n);
_arb_vec_indeterminate(Q->coeffs, n);
_arb_poly_set_length(Q, n);
return;
}
if (A->length == 0)
{
arb_poly_zero(Q);
return;
}
if (Q == A || Q == B)
{
arb_poly_t t;
arb_poly_init(t);
arb_poly_div_series(t, A, B, n, prec);
arb_poly_swap(Q, t);
arb_poly_clear(t);
return;
}
arb_poly_fit_length(Q, n);
_arb_poly_div_series(Q->coeffs, A->coeffs, A->length, B->coeffs, B->length, n, prec);
_arb_poly_set_length(Q, n);
_arb_poly_normalise(Q);
}
/* F = 1 + U + U^2 + U^3 + ... = 1/(1-U)
U = product of (1 + |A-B|/(|B[0] - |B[1:]|)
product of (1 / (|B[0] - |B[1:]|))
* |Z|
*/
void
acb_hypgeom_pfq_series_bound_factor(arb_poly_t F,
const acb_poly_struct * a, long p,
const acb_poly_struct * b, long q,
const acb_poly_t z,
long n, long len, long prec)
{
long i;
arb_poly_t T, U, V;
acb_poly_t BN, AB;
/* not convergent */
if (p > q)
{
arb_poly_fit_length(F, len);
_arb_vec_indeterminate(F->coeffs, len);
_arb_poly_set_length(F, len);
return;
}
arb_poly_init(T);
arb_poly_init(U);
arb_poly_init(V);
acb_poly_init(BN);
acb_poly_init(AB);
acb_poly_majorant(U, z, prec);
for (i = 0; i < q; i++)
{
acb_poly_add_si(BN, b + i, n, prec);
if (acb_poly_length(BN) != 0 &&
arb_is_positive(acb_realref(BN->coeffs)))
{
if (i < p)
{
/* 1 + |a-b|/reciprocal_majorant(b + n) */
acb_poly_sub(AB, a + i, b + i, prec);
acb_poly_majorant(T, AB, prec);
acb_poly_reciprocal_majorant(V, BN, prec);
arb_poly_div_series(T, T, V, len, prec);
arb_poly_add_si(T, T, 1, prec);
arb_poly_mullow(U, U, T, len, prec);
}
else
{
acb_poly_reciprocal_majorant(T, BN, prec);
arb_poly_div_series(U, U, T, len, prec);
}
}
else
{
arb_poly_fit_length(U, len);
_arb_vec_indeterminate(U->coeffs, len);
_arb_poly_set_length(U, len);
break;
}
}
/* F = 1/(1-U) */
arb_poly_geometric_sum(F, U, len, prec);
arb_poly_clear(T);
arb_poly_clear(U);
arb_poly_clear(V);
acb_poly_clear(BN);
acb_poly_clear(AB);
}
int main()
{
slong iter;
flint_rand_t state;
flint_printf("div_series....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 10000 * arb_test_multiplier(); iter++)
{
slong m, n, p, qbits, rbits1, rbits2;
fmpq_poly_t A, B, C;
arb_poly_t a, b, c, d;
qbits = 2 + n_randint(state, 200);
rbits1 = 2 + n_randint(state, 200);
rbits2 = 2 + n_randint(state, 200);
m = 1 + n_randint(state, 20);
n = 1 + n_randint(state, 20);
p = 1 + n_randint(state, 20);
fmpq_poly_init(A);
fmpq_poly_init(B);
fmpq_poly_init(C);
arb_poly_init(a);
arb_poly_init(b);
arb_poly_init(c);
arb_poly_init(d);
fmpq_poly_randtest(A, state, m, qbits);
do {
fmpq_poly_randtest_not_zero(B, state, n, qbits);
} while (B->coeffs[0] == 0);
fmpq_poly_div_series(C, A, B, p);
arb_poly_set_fmpq_poly(a, A, rbits1);
arb_poly_set_fmpq_poly(b, B, rbits1);
arb_poly_div_series(c, a, b, p, rbits2);
if (!arb_poly_contains_fmpq_poly(c, C))
{
flint_printf("FAIL\n\n");
flint_printf("bits2 = %wd\n", rbits2);
flint_printf("A = "); fmpq_poly_print(A); flint_printf("\n\n");
flint_printf("B = "); fmpq_poly_print(B); flint_printf("\n\n");
flint_printf("C = "); fmpq_poly_print(C); flint_printf("\n\n");
flint_printf("a = "); arb_poly_printd(a, 15); flint_printf("\n\n");
flint_printf("b = "); arb_poly_printd(b, 15); flint_printf("\n\n");
flint_printf("c = "); arb_poly_printd(c, 15); flint_printf("\n\n");
flint_abort();
}
arb_poly_set(d, a);
arb_poly_div_series(d, d, b, p, rbits2);
if (!arb_poly_equal(d, c))
{
flint_printf("FAIL (aliasing 1)\n\n");
flint_abort();
}
arb_poly_set(d, b);
arb_poly_div_series(d, a, d, p, rbits2);
if (!arb_poly_equal(d, c))
{
flint_printf("FAIL (aliasing 2)\n\n");
flint_abort();
}
arb_poly_set(d, b);
arb_poly_div_series(c, d, d, p, rbits2);
arb_poly_div_series(d, d, d, p, rbits2);
if (!arb_poly_equal(d, c))
{
flint_printf("FAIL (aliasing 3)\n\n");
flint_abort();
}
fmpq_poly_clear(A);
fmpq_poly_clear(B);
fmpq_poly_clear(C);
arb_poly_clear(a);
arb_poly_clear(b);
arb_poly_clear(c);
arb_poly_clear(d);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}
int main()
{
slong iter;
flint_rand_t state;
flint_printf("atan_series....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 10000; iter++)
{
slong m, n, qbits, rbits1, rbits2;
fmpq_poly_t A;
arb_poly_t a, b, c, d;
qbits = 2 + n_randint(state, 200);
rbits1 = 2 + n_randint(state, 200);
rbits2 = 2 + n_randint(state, 200);
m = 1 + n_randint(state, 30);
n = 1 + n_randint(state, 30);
fmpq_poly_init(A);
arb_poly_init(a);
arb_poly_init(b);
arb_poly_init(c);
arb_poly_init(d);
fmpq_poly_randtest(A, state, m, qbits);
arb_poly_set_fmpq_poly(a, A, rbits1);
arb_poly_randtest(b, state, 1 + n_randint(state, 30), rbits1, 5);
arb_poly_atan_series(b, a, n, rbits2);
/* Check 2 atan(x) = atan(2x/(1-x^2)) + C */
arb_poly_mullow(c, a, a, n, rbits2);
arb_poly_one(d);
arb_poly_sub(c, d, c, rbits2);
arb_poly_add(d, a, a, rbits2);
if (arb_poly_length(c) != 0)
{
arb_poly_div_series(c, d, c, n, rbits2);
arb_poly_atan_series(c, c, n, rbits2);
arb_poly_add(d, b, b, rbits2);
/* TODO: also check the first coefficient */
arb_poly_set_coeff_si(c, 0, 0);
arb_poly_set_coeff_si(d, 0, 0);
if (!arb_poly_overlaps(c, d))
{
flint_printf("FAIL\n\n");
flint_printf("bits2 = %wd\n", rbits2);
flint_printf("A = "); fmpq_poly_print(A); flint_printf("\n\n");
flint_printf("a = "); arb_poly_printd(a, 15); flint_printf("\n\n");
flint_printf("b = "); arb_poly_printd(b, 15); flint_printf("\n\n");
flint_printf("c = "); arb_poly_printd(c, 15); flint_printf("\n\n");
flint_printf("d = "); arb_poly_printd(d, 15); flint_printf("\n\n");
abort();
}
}
arb_poly_atan_series(a, a, n, rbits2);
if (!arb_poly_equal(a, b))
{
flint_printf("FAIL (aliasing)\n\n");
abort();
}
fmpq_poly_clear(A);
arb_poly_clear(a);
arb_poly_clear(b);
arb_poly_clear(c);
arb_poly_clear(d);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}
