void
arb_poly_mul(arb_poly_t res, const arb_poly_t poly1,
const arb_poly_t poly2, slong prec)
{
slong len_out;
if ((poly1->length == 0) || (poly2->length == 0))
{
arb_poly_zero(res);
return;
}
len_out = poly1->length + poly2->length - 1;
if (res == poly1 || res == poly2)
{
arb_poly_t temp;
arb_poly_init2(temp, len_out);
_arb_poly_mul(temp->coeffs, poly1->coeffs, poly1->length,
poly2->coeffs, poly2->length, prec);
arb_poly_swap(res, temp);
arb_poly_clear(temp);
}
else
{
arb_poly_fit_length(res, len_out);
_arb_poly_mul(res->coeffs, poly1->coeffs, poly1->length,
poly2->coeffs, poly2->length, prec);
}
_arb_poly_set_length(res, len_out);
_arb_poly_normalise(res);
}
void
arb_poly_revert_series(arb_poly_t Qinv,
const arb_poly_t Q, slong n, slong prec)
{
slong Qlen = Q->length;
if (Qlen < 2 || !arb_is_zero(Q->coeffs)
|| arb_contains_zero(Q->coeffs + 1))
{
flint_printf("Exception (arb_poly_revert_series). Input must \n"
"have zero constant term and nonzero coefficient of x^1.\n");
abort();
}
if (Qinv != Q)
{
arb_poly_fit_length(Qinv, n);
_arb_poly_revert_series(Qinv->coeffs, Q->coeffs, Qlen, n, prec);
}
else
{
arb_poly_t t;
arb_poly_init2(t, n);
_arb_poly_revert_series(t->coeffs, Q->coeffs, Qlen, n, prec);
arb_poly_swap(Qinv, t);
arb_poly_clear(t);
}
_arb_poly_set_length(Qinv, n);
_arb_poly_normalise(Qinv);
}
void
arb_poly_binomial_transform(arb_poly_t b, const arb_poly_t a, slong len, slong prec)
{
if (len == 0 || a->length == 0)
{
arb_poly_zero(b);
return;
}
if (b == a)
{
arb_poly_t c;
arb_poly_init2(c, len);
_arb_poly_binomial_transform(c->coeffs, a->coeffs, a->length, len, prec);
arb_poly_swap(b, c);
arb_poly_clear(c);
}
else
{
arb_poly_fit_length(b, len);
_arb_poly_binomial_transform(b->coeffs, a->coeffs, a->length, len, prec);
}
_arb_poly_set_length(b, len);
_arb_poly_normalise(b);
}
void
arb_poly_compose_series(arb_poly_t res,
const arb_poly_t poly1,
const arb_poly_t poly2, slong n, slong prec)
{
slong len1 = poly1->length;
slong len2 = poly2->length;
slong lenr;
if (len2 != 0 && !arb_is_zero(poly2->coeffs))
{
flint_printf("exception: compose_series: inner "
"polynomial must have zero constant term\n");
abort();
}
if (len1 == 0 || n == 0)
{
arb_poly_zero(res);
return;
}
if (len2 == 0 || len1 == 1)
{
arb_poly_set_arb(res, poly1->coeffs);
return;
}
lenr = FLINT_MIN((len1 - 1) * (len2 - 1) + 1, n);
len1 = FLINT_MIN(len1, lenr);
len2 = FLINT_MIN(len2, lenr);
if ((res != poly1) && (res != poly2))
{
arb_poly_fit_length(res, lenr);
_arb_poly_compose_series(res->coeffs, poly1->coeffs, len1,
poly2->coeffs, len2, lenr, prec);
_arb_poly_set_length(res, lenr);
_arb_poly_normalise(res);
}
else
{
arb_poly_t t;
arb_poly_init2(t, lenr);
_arb_poly_compose_series(t->coeffs, poly1->coeffs, len1,
poly2->coeffs, len2, lenr, prec);
_arb_poly_set_length(t, lenr);
_arb_poly_normalise(t);
arb_poly_swap(res, t);
arb_poly_clear(t);
}
}
void
arb_poly_pow_ui_trunc_binexp(arb_poly_t res,
const arb_poly_t poly, ulong exp, slong len, slong prec)
{
slong flen, rlen;
flen = poly->length;
if (exp == 0 && len != 0)
{
arb_poly_one(res);
}
else if (flen == 0 || len == 0)
{
arb_poly_zero(res);
}
else
{
rlen = poly_pow_length(flen, exp, len);
if (res != poly)
{
arb_poly_fit_length(res, rlen);
_arb_poly_pow_ui_trunc_binexp(res->coeffs,
poly->coeffs, flen, exp, rlen, prec);
_arb_poly_set_length(res, rlen);
_arb_poly_normalise(res);
}
else
{
arb_poly_t t;
arb_poly_init2(t, rlen);
_arb_poly_pow_ui_trunc_binexp(t->coeffs,
poly->coeffs, flen, exp, rlen, prec);
_arb_poly_set_length(t, rlen);
_arb_poly_normalise(t);
arb_poly_swap(res, t);
arb_poly_clear(t);
}
}
}
void
arb_poly_mullow_block(arb_poly_t res, const arb_poly_t poly1,
const arb_poly_t poly2, slong n, slong prec)
{
slong xlen, ylen, zlen;
xlen = poly1->length;
ylen = poly2->length;
if (xlen == 0 || ylen == 0 || n == 0)
{
arb_poly_zero(res);
return;
}
xlen = FLINT_MIN(xlen, n);
ylen = FLINT_MIN(ylen, n);
zlen = FLINT_MIN(xlen + ylen - 1, n);
if (res == poly1 || res == poly2)
{
arb_poly_t tmp;
arb_poly_init2(tmp, zlen);
_arb_poly_mullow_block(tmp->coeffs, poly1->coeffs, xlen,
poly2->coeffs, ylen, zlen, prec);
arb_poly_swap(res, tmp);
arb_poly_clear(tmp);
}
else
{
arb_poly_fit_length(res, zlen);
_arb_poly_mullow_block(res->coeffs, poly1->coeffs, xlen,
poly2->coeffs, ylen, zlen, prec);
}
_arb_poly_set_length(res, zlen);
_arb_poly_normalise(res);
}
void arb_poly_compose(arb_poly_t res,
const arb_poly_t poly1, const arb_poly_t poly2, slong prec)
{
const slong len1 = poly1->length;
const slong len2 = poly2->length;
if (len1 == 0)
{
arb_poly_zero(res);
}
else if (len1 == 1 || len2 == 0)
{
arb_poly_set_arb(res, poly1->coeffs);
}
else
{
const slong lenr = (len1 - 1) * (len2 - 1) + 1;
if (res != poly1 && res != poly2)
{
arb_poly_fit_length(res, lenr);
_arb_poly_compose(res->coeffs, poly1->coeffs, len1,
poly2->coeffs, len2, prec);
}
else
{
arb_poly_t t;
arb_poly_init2(t, lenr);
_arb_poly_compose(t->coeffs, poly1->coeffs, len1,
poly2->coeffs, len2, prec);
arb_poly_swap(res, t);
arb_poly_clear(t);
}
_arb_poly_set_length(res, lenr);
_arb_poly_normalise(res);
}
}
void
arb_poly_mullow_classical(arb_poly_t res, const arb_poly_t poly1,
const arb_poly_t poly2,
long n, long prec)
{
long len_out;
if (poly1->length == 0 || poly2->length == 0 || n == 0)
{
arb_poly_zero(res);
return;
}
len_out = poly1->length + poly2->length - 1;
if (n > len_out)
n = len_out;
if (res == poly1 || res == poly2)
{
arb_poly_t t;
arb_poly_init2(t, n);
_arb_poly_mullow_classical(t->coeffs, poly1->coeffs, poly1->length,
poly2->coeffs, poly2->length, n, prec);
arb_poly_swap(res, t);
arb_poly_clear(t);
}
else
{
arb_poly_fit_length(res, n);
_arb_poly_mullow_classical(res->coeffs, poly1->coeffs, poly1->length,
poly2->coeffs, poly2->length, n, prec);
}
_arb_poly_set_length(res, n);
_arb_poly_normalise(res);
}
