#include "fmpz.h"
#include "fmpz_vec.h"
#include "fmpq_poly.h"
void _fmpq_poly_log_series(fmpz * g, fmpz_t gden,
const fmpz * f, const fmpz_t fden, slong flen, slong n)
{
fmpz * f_diff;
fmpz * f_inv;
fmpz_t f_diff_den;
fmpz_t f_inv_den;
flen = FLINT_MIN(flen, n);
f_diff = _fmpz_vec_init(flen - 1);
f_inv = _fmpz_vec_init(n);
fmpz_init(f_diff_den);
fmpz_init(f_inv_den);
_fmpq_poly_derivative(f_diff, f_diff_den, f, fden, flen);
_fmpq_poly_inv_series(f_inv, f_inv_den, f, fden, flen, n);
_fmpq_poly_mullow(g, gden, f_inv, f_inv_den, n - 1,
f_diff, f_diff_den, flen - 1, n - 1);
_fmpq_poly_canonicalise(g, gden, n - 1);
_fmpq_poly_integral(g, gden, g, gden, n);
_fmpz_vec_clear(f_diff, flen - 1);
_fmpz_vec_clear(f_inv, n);
fmpz_clear(f_diff_den);
fmpz_clear(f_inv_den);
}
void
fmpq_poly_log_series(fmpq_poly_t res, const fmpq_poly_t f, slong n)
{
slong flen = f->length;
if (flen < 1 || !fmpz_equal(f->coeffs, f->den))
{
flint_throw(FLINT_ERROR, "Exception (fmpq_poly_log_series). Constant term != 1.\n");
}
if (flen == 1 || n < 2)
{
fmpq_poly_zero(res);
return;
}
fmpq_poly_fit_length(res, n);
_fmpq_poly_log_series(res->coeffs, res->den, f->coeffs, f->den, f->length, n);
_fmpq_poly_set_length(res, n);
_fmpq_poly_normalise(res);
}