pqc/external/flint-2.4.3/padic_mat/set_fmpq_mat.c
2014-05-24 23:16:06 +02:00

95 lines
3.2 KiB
C

/*=============================================================================
This file is part of FLINT.
FLINT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
FLINT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with FLINT; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
=============================================================================*/
/******************************************************************************
Copyright (C) 2012, 2013 Sebastian Pancratz
******************************************************************************/
#include <limits.h>
#include "padic_mat.h"
void padic_mat_set_fmpq_mat(padic_mat_t B,
const fmpq_mat_t A, const padic_ctx_t ctx)
{
if (!fmpq_mat_is_empty(A))
{
const slong N = padic_mat_prec(B);
slong i, j, m = WORD_MAX, v, w;
fmpz_t f, g, s, t;
fmpz_init(f);
fmpz_init(g);
fmpz_init(s);
fmpz_init(t);
/* Find min valuation m */
for (i = 0; i < A->r; i++)
for (j = 0; j < A->c; j++)
if (!fmpq_is_zero(fmpq_mat_entry(A, i, j)))
{
v = fmpz_remove(t, fmpq_mat_entry_num(A, i, j), ctx->p);
w = fmpz_remove(t, fmpq_mat_entry_den(A, i, j), ctx->p);
m = FLINT_MIN(m, v - w);
}
if (m >= N)
{
padic_mat_zero(B);
}
else
{
for (i = 0; i < A->r; i++)
for (j = 0; j < A->c; j++)
if (fmpq_is_zero(fmpq_mat_entry(A, i, j)))
{
fmpz_zero(padic_mat_entry(B, i, j));
}
else
{
v = fmpz_remove(s, fmpq_mat_entry_num(A, i, j), ctx->p);
w = fmpz_remove(t, fmpq_mat_entry_den(A, i, j), ctx->p);
if (v - w >= N)
{
fmpz_zero(padic_mat_entry(B, i, j));
}
else
{
fmpz_pow_ui(f, ctx->p, (v - w) - m);
fmpz_pow_ui(g, ctx->p, N - (v - w));
_padic_inv(t, t, ctx->p, N - (v - w));
fmpz_mul(padic_mat_entry(B, i, j), s, t);
fmpz_mod(padic_mat_entry(B, i, j), padic_mat_entry(B, i, j), g);
fmpz_mul(padic_mat_entry(B, i, j), padic_mat_entry(B, i, j), f);
}
}
padic_mat_val(B) = m;
}
fmpz_clear(f);
fmpz_clear(g);
fmpz_clear(s);
fmpz_clear(t);
}
}