add arf_sosq (sum of squares)

This commit is contained in:
Fredrik Johansson 2017-02-18 15:56:00 +01:00
parent adf3650500
commit 109afaab0f
4 changed files with 251 additions and 0 deletions

2
arf.h
View file

@ -1063,6 +1063,8 @@ arf_submul_fmpz(arf_ptr z, arf_srcptr x, const fmpz_t y, slong prec, arf_rnd_t r
return arf_submul_mpz(z, x, COEFF_TO_PTR(*y), prec, rnd); return arf_submul_mpz(z, x, COEFF_TO_PTR(*y), prec, rnd);
} }
int arf_sosq(arf_t z, const arf_t x, const arf_t y, slong prec, arf_rnd_t rnd);
int arf_div(arf_ptr z, arf_srcptr x, arf_srcptr y, slong prec, arf_rnd_t rnd); int arf_div(arf_ptr z, arf_srcptr x, arf_srcptr y, slong prec, arf_rnd_t rnd);
ARF_INLINE int ARF_INLINE int

82
arf/sosq.c Normal file
View file

@ -0,0 +1,82 @@
/*
Copyright (C) 2017 Fredrik Johansson
This file is part of Arb.
Arb is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version. See <http://www.gnu.org/licenses/>.
*/
#include "arf.h"
int
arf_sosq(arf_t res, const arf_t a, const arf_t b, slong prec, arf_rnd_t rnd)
{
if (arf_is_special(a) || arf_is_special(b))
{
if (arf_is_zero(a))
return arf_mul(res, b, b, prec, rnd);
if (arf_is_zero(b))
return arf_mul(res, a, a, prec, rnd);
if (arf_is_nan(a) || arf_is_nan(b))
arf_nan(res);
else
arf_pos_inf(res);
return 0;
}
else
{
mp_srcptr ap, bp;
int inexact;
mp_ptr tmp, aap, bbp;
mp_size_t an, bn, aan, bbn, alloc;
slong shift;
fmpz_t texp, uexp;
ARF_MUL_TMP_DECL
ARF_GET_MPN_READONLY(ap, an, a);
ARF_GET_MPN_READONLY(bp, bn, b);
fmpz_init(texp);
fmpz_init(uexp);
_fmpz_add2_fast(texp, ARF_EXPREF(a), ARF_EXPREF(a), 0);
_fmpz_add2_fast(uexp, ARF_EXPREF(b), ARF_EXPREF(b), 0);
shift = _fmpz_sub_small(texp, uexp);
aan = 2 * an;
bbn = 2 * bn;
alloc = aan + bbn;
ARF_MUL_TMP_ALLOC(tmp, alloc)
aap = tmp;
bbp = tmp + aan;
ARF_MPN_MUL(aap, ap, an, ap, an)
aan -= (aap[0] == 0);
aap += (aap[0] == 0);
ARF_MPN_MUL(bbp, bp, bn, bp, bn)
bbn -= (bbp[0] == 0);
bbp += (bbp[0] == 0);
if (shift >= 0)
inexact = _arf_add_mpn(res, aap, aan, 0, texp,
bbp, bbn, 0, shift, prec, rnd);
else
inexact = _arf_add_mpn(res, bbp, bbn, 0, uexp,
aap, aan, 0, -shift, prec, rnd);
ARF_MUL_TMP_FREE(tmp, alloc)
fmpz_clear(texp);
fmpz_clear(uexp);
return inexact;
}
}

162
arf/test/t-sosq.c Normal file
View file

@ -0,0 +1,162 @@
/*
Copyright (C) 2012 Fredrik Johansson
This file is part of Arb.
Arb is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version. See <http://www.gnu.org/licenses/>.
*/
#include "arf.h"
int
arf_sosq_naive(arf_t z, const arf_t x, const arf_t y, slong prec, arf_rnd_t rnd)
{
arf_t t;
int inexact;
arf_init(t);
arf_mul(t, x, x, ARF_PREC_EXACT, ARF_RND_DOWN);
arf_mul(z, y, y, ARF_PREC_EXACT, ARF_RND_DOWN);
inexact = arf_add(z, z, t, prec, rnd);
arf_clear(t);
return inexact;
}
int main()
{
slong iter, iter2;
flint_rand_t state;
flint_printf("sosq....");
fflush(stdout);
flint_randinit(state);
for (iter = 0; iter < 1000 * arb_test_multiplier(); iter++)
{
arf_t x, y, z, v;
slong prec, r1, r2;
arf_rnd_t rnd;
arf_init(x);
arf_init(y);
arf_init(z);
arf_init(v);
for (iter2 = 0; iter2 < 100; iter2++)
{
arf_randtest_special(x, state, 2000, 100);
arf_randtest_special(y, state, 2000, 100);
arf_randtest_special(z, state, 2000, 100);
arf_randtest_special(v, state, 2000, 100);
prec = 2 + n_randint(state, 2000);
if (n_randint(state, 10) == 0 &&
fmpz_bits(ARF_EXPREF(x)) < 10 &&
fmpz_bits(ARF_EXPREF(y)) < 10)
{
prec = ARF_PREC_EXACT;
}
switch (n_randint(state, 5))
{
case 0: rnd = ARF_RND_DOWN; break;
case 1: rnd = ARF_RND_UP; break;
case 2: rnd = ARF_RND_FLOOR; break;
case 3: rnd = ARF_RND_CEIL; break;
default: rnd = ARF_RND_NEAR; break;
}
switch (n_randint(state, 5))
{
case 0:
r1 = arf_sosq(z, x, y, prec, rnd);
r2 = arf_sosq_naive(v, x, y, prec, rnd);
if (!arf_equal(z, v) || r1 != r2)
{
flint_printf("FAIL!\n");
flint_printf("prec = %wd, rnd = %d\n\n", prec, rnd);
flint_printf("x = "); arf_print(x); flint_printf("\n\n");
flint_printf("y = "); arf_print(y); flint_printf("\n\n");
flint_printf("z = "); arf_print(z); flint_printf("\n\n");
flint_printf("v = "); arf_print(v); flint_printf("\n\n");
flint_printf("r1 = %wd, r2 = %wd\n", r1, r2);
abort();
}
break;
case 1:
r1 = arf_sosq(z, x, x, prec, rnd);
r2 = arf_sosq_naive(v, x, x, prec, rnd);
if (!arf_equal(z, v) || r1 != r2)
{
flint_printf("FAIL (aliasing 1)!\n");
flint_printf("prec = %wd, rnd = %d\n\n", prec, rnd);
flint_printf("x = "); arf_print(x); flint_printf("\n\n");
flint_printf("z = "); arf_print(z); flint_printf("\n\n");
flint_printf("v = "); arf_print(v); flint_printf("\n\n");
flint_printf("r1 = %wd, r2 = %wd\n", r1, r2);
abort();
}
break;
case 2:
r2 = arf_sosq_naive(v, x, y, prec, rnd);
r1 = arf_sosq(x, x, y, prec, rnd);
if (!arf_equal(v, x) || r1 != r2)
{
flint_printf("FAIL (aliasing 2)!\n");
flint_printf("prec = %wd, rnd = %d\n\n", prec, rnd);
flint_printf("v = "); arf_print(v); flint_printf("\n\n");
flint_printf("x = "); arf_print(x); flint_printf("\n\n");
flint_printf("r1 = %wd, r2 = %wd\n", r1, r2);
abort();
}
break;
case 3:
r2 = arf_sosq_naive(v, x, y, prec, rnd);
r1 = arf_sosq(y, x, y, prec, rnd);
if (!arf_equal(v, y) || r1 != r2)
{
flint_printf("FAIL (aliasing 3)!\n");
flint_printf("prec = %wd, rnd = %d\n\n", prec, rnd);
flint_printf("x = "); arf_print(x); flint_printf("\n\n");
flint_printf("y = "); arf_print(y); flint_printf("\n\n");
flint_printf("v = "); arf_print(v); flint_printf("\n\n");
flint_printf("r1 = %wd, r2 = %wd\n", r1, r2);
abort();
}
break;
default:
r2 = arf_sosq_naive(v, x, x, prec, rnd);
r1 = arf_sosq(x, x, x, prec, rnd);
if (!arf_equal(v, x) || r1 != r2)
{
flint_printf("FAIL (aliasing 4)!\n");
flint_printf("prec = %wd, rnd = %d\n\n", prec, rnd);
flint_printf("x = "); arf_print(x); flint_printf("\n\n");
flint_printf("v = "); arf_print(v); flint_printf("\n\n");
flint_printf("z = "); arf_print(z); flint_printf("\n\n");
flint_printf("r1 = %wd, r2 = %wd\n", r1, r2);
abort();
}
break;
}
}
arf_clear(x);
arf_clear(y);
arf_clear(z);
arf_clear(v);
}
flint_randclear(state);
flint_cleanup();
flint_printf("PASS\n");
return EXIT_SUCCESS;
}

View file

@ -596,6 +596,11 @@ Addition and multiplication
Sets `z = z - x \times y`, rounded to *prec* bits in the direction specified by *rnd*, Sets `z = z - x \times y`, rounded to *prec* bits in the direction specified by *rnd*,
returning nonzero iff the operation is inexact. returning nonzero iff the operation is inexact.
.. function:: int arf_sosq(arf_t z, const arf_t x, const arf_t y, slong prec, arf_rnd_t rnd)
Sets `z = x^2 + y^2`, rounded to *prec* bits in the direction specified by *rnd*,
returning nonzero iff the operation is inexact.
Summation Summation
------------------------------------------------------------------------------- -------------------------------------------------------------------------------