mirror of
https://github.com/vale981/arb
synced 2025-03-05 09:21:38 -05:00
97 lines
2.2 KiB
C
97 lines
2.2 KiB
C
/*
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Copyright (C) 2016 Pascal Molin
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This file is part of Arb.
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Arb is free software: you can redistribute it and/or modify it under
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the terms of the GNU Lesser General Public License (LGPL) as published
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by the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version. See <http://www.gnu.org/licenses/>.
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*/
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#include "acb_poly.h"
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#include "acb_dft.h"
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/* all roots are already computed, w != v */
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void
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_acb_dft_naive(acb_ptr w, acb_srcptr v, slong dv, acb_srcptr z, slong dz, slong len, slong prec)
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{
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slong i, j;
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acb_ptr wi, v1 = NULL;
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acb_srcptr vj;
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if (w == v)
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{
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flint_printf("\n_acb_dft_naive: does not accept aliasing\n");
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abort();
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}
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for (i = 0, wi = w; i < len; i++, wi++)
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{
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acb_zero(wi);
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for (j = 0, vj = v; j < len; j++, vj += dv)
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acb_addmul(wi, vj, z + dz * (i * j % len), prec);
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}
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if (v1)
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_acb_vec_clear(v1, len);
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}
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void
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acb_dft_naive_precomp(acb_ptr w, acb_srcptr v, const acb_dft_naive_t pol, slong prec)
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{
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if (v == w)
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{
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acb_ptr v1 = _acb_vec_init(pol->n);
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_acb_vec_set(v1, v, pol->n);
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_acb_dft_naive(w, v1, pol->dv, pol->z, pol->dz, pol->n, prec);
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_acb_vec_clear(v1, pol->n);
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}
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else
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_acb_dft_naive(w, v, pol->dv, pol->z, pol->dz, pol->n, prec);
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}
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void
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acb_dft_naive(acb_ptr w, acb_srcptr v, slong len, slong prec)
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{
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acb_ptr z, v1 = NULL;
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z = _acb_vec_init(len);
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_acb_vec_unit_roots(z, -len, len, prec);
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if (w == v)
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{
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v1 = _acb_vec_init(len);
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_acb_vec_set(v1, v, len);
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v = v1;
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}
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_acb_dft_naive(w, v, 1, z, 1, len, prec);
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if (v1)
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_acb_vec_clear(v1, len);
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_acb_vec_clear(z, len);
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}
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void
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_acb_dft_naive_init(acb_dft_naive_t pol, slong dv, acb_ptr z, slong dz, slong len, slong prec)
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{
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pol->n = len;
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pol->dv = dv;
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if (z == NULL)
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{
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if (DFT_VERB)
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flint_printf("dft_naive: init z[%wd]\n",len);
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pol->z = _acb_vec_init(len);
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_acb_vec_unit_roots(pol->z, -len, len, prec);
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pol->dz = 1;
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pol->zclear = 1;
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}
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else
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{
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pol->z = z;
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pol->dz = dz;
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pol->zclear = 0;
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}
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}
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