1 /*
2 Copyright (C) 2012 Sebastian Pancratz
3
4 This file is part of FLINT.
5
6 FLINT is free software: you can redistribute it and/or modify it under
7 the terms of the GNU Lesser General Public License (LGPL) as published
8 by the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version. See <http://www.gnu.org/licenses/>.
10 */
11
12 #include "fmpz_mod_poly.h"
13 #include "padic_poly.h"
14
_padic_poly_derivative(fmpz * rop,slong * rval,slong N,const fmpz * op,slong val,slong len,const padic_ctx_t ctx)15 void _padic_poly_derivative(fmpz *rop, slong *rval, slong N,
16 const fmpz *op, slong val, slong len,
17 const padic_ctx_t ctx)
18 {
19 fmpz_t pow;
20 int alloc;
21
22 _fmpz_poly_derivative(rop, op, len);
23 *rval = val;
24
25 alloc = _padic_ctx_pow_ui(pow, N - *rval, ctx);
26
27 _fmpz_vec_scalar_mod_fmpz(rop, rop, len - 1, pow);
28 _padic_poly_canonicalise(rop, rval, len - 1, ctx->p);
29
30 if (alloc)
31 fmpz_clear(pow);
32 }
33
padic_poly_derivative(padic_poly_t rop,const padic_poly_t op,const padic_ctx_t ctx)34 void padic_poly_derivative(padic_poly_t rop,
35 const padic_poly_t op, const padic_ctx_t ctx)
36 {
37 const slong len = op->length;
38
39 if (len < 2 || op->val >= rop->N)
40 {
41 padic_poly_zero(rop);
42 }
43 else
44 {
45 padic_poly_fit_length(rop, len - 1);
46 _padic_poly_derivative(rop->coeffs, &(rop->val), rop->N,
47 op->coeffs, op->val, len, ctx);
48 _padic_poly_set_length(rop, len - 1);
49 _padic_poly_normalise(rop);
50 }
51 }
52
53