diff options
author | Peter Breitenlohner <peb@mppmu.mpg.de> | 2015-06-20 10:38:01 +0000 |
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committer | Peter Breitenlohner <peb@mppmu.mpg.de> | 2015-06-20 10:38:01 +0000 |
commit | 265eb77be2ea7991cb155d175740f1978b9aff45 (patch) | |
tree | 50312a038421405d62654d95016e16f1ffc46499 /Build/source/libs/mpfr/mpfr-3.1.2/src/yn.c | |
parent | cd9d1f5f065d7a8bb787f683ffac1f907356a285 (diff) |
mpfr 3.1.3
git-svn-id: svn://tug.org/texlive/trunk@37627 c570f23f-e606-0410-a88d-b1316a301751
Diffstat (limited to 'Build/source/libs/mpfr/mpfr-3.1.2/src/yn.c')
-rw-r--r-- | Build/source/libs/mpfr/mpfr-3.1.2/src/yn.c | 426 |
1 files changed, 0 insertions, 426 deletions
diff --git a/Build/source/libs/mpfr/mpfr-3.1.2/src/yn.c b/Build/source/libs/mpfr/mpfr-3.1.2/src/yn.c deleted file mode 100644 index 24d3e176e20..00000000000 --- a/Build/source/libs/mpfr/mpfr-3.1.2/src/yn.c +++ /dev/null @@ -1,426 +0,0 @@ -/* mpfr_y0, mpfr_y1, mpfr_yn -- Bessel functions of 2nd kind, integer order. - http://www.opengroup.org/onlinepubs/009695399/functions/y0.html - -Copyright 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc. -Contributed by the AriC and Caramel projects, INRIA. - -This file is part of the GNU MPFR Library. - -The GNU MPFR Library is free software; you can redistribute it and/or modify -it under the terms of the GNU Lesser General Public License as published by -the Free Software Foundation; either version 3 of the License, or (at your -option) any later version. - -The GNU MPFR Library 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 Lesser General Public -License for more details. - -You should have received a copy of the GNU Lesser General Public License -along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see -http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., -51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */ - -#define MPFR_NEED_LONGLONG_H -#include "mpfr-impl.h" - -static int mpfr_yn_asympt (mpfr_ptr, long, mpfr_srcptr, mpfr_rnd_t); - -int -mpfr_y0 (mpfr_ptr res, mpfr_srcptr z, mpfr_rnd_t r) -{ - return mpfr_yn (res, 0, z, r); -} - -int -mpfr_y1 (mpfr_ptr res, mpfr_srcptr z, mpfr_rnd_t r) -{ - return mpfr_yn (res, 1, z, r); -} - -/* compute in s an approximation of S1 = sum((n-k)!/k!*y^k,k=0..n) - return e >= 0 the exponent difference between the maximal value of |s| - during the for loop and the final value of |s|. -*/ -static mpfr_exp_t -mpfr_yn_s1 (mpfr_ptr s, mpfr_srcptr y, unsigned long n) -{ - unsigned long k; - mpz_t f; - mpfr_exp_t e, emax; - - mpz_init_set_ui (f, 1); - /* we compute n!*S1 = sum(a[k]*y^k,k=0..n) where a[k] = n!*(n-k)!/k!, - a[0] = (n!)^2, a[1] = n!*(n-1)!, ..., a[n-1] = n, a[n] = 1 */ - mpfr_set_ui (s, 1, MPFR_RNDN); /* a[n] */ - emax = MPFR_EXP(s); - for (k = n; k-- > 0;) - { - /* a[k]/a[k+1] = (n-k)!/k!/(n-(k+1))!*(k+1)! = (k+1)*(n-k) */ - mpfr_mul (s, s, y, MPFR_RNDN); - mpz_mul_ui (f, f, n - k); - mpz_mul_ui (f, f, k + 1); - /* invariant: f = a[k] */ - mpfr_add_z (s, s, f, MPFR_RNDN); - e = MPFR_EXP(s); - if (e > emax) - emax = e; - } - /* now we have f = (n!)^2 */ - mpz_sqrt (f, f); - mpfr_div_z (s, s, f, MPFR_RNDN); - mpz_clear (f); - return emax - MPFR_EXP(s); -} - -/* compute in s an approximation of - S3 = c*sum((h(k)+h(n+k))*y^k/k!/(n+k)!,k=0..infinity) - where h(k) = 1 + 1/2 + ... + 1/k - k=0: h(n) - k=1: 1+h(n+1) - k=2: 3/2+h(n+2) - Returns e such that the error is bounded by 2^e ulp(s). -*/ -static mpfr_exp_t -mpfr_yn_s3 (mpfr_ptr s, mpfr_srcptr y, mpfr_srcptr c, unsigned long n) -{ - unsigned long k, zz; - mpfr_t t, u; - mpz_t p, q; /* p/q will store h(k)+h(n+k) */ - mpfr_exp_t exps, expU; - - zz = mpfr_get_ui (y, MPFR_RNDU); /* y = z^2/4 */ - MPFR_ASSERTN (zz < ULONG_MAX - 2); - zz += 2; /* z^2 <= 2^zz */ - mpz_init_set_ui (p, 0); - mpz_init_set_ui (q, 1); - /* initialize p/q to h(n) */ - for (k = 1; k <= n; k++) - { - /* p/q + 1/k = (k*p+q)/(q*k) */ - mpz_mul_ui (p, p, k); - mpz_add (p, p, q); - mpz_mul_ui (q, q, k); - } - mpfr_init2 (t, MPFR_PREC(s)); - mpfr_init2 (u, MPFR_PREC(s)); - mpfr_fac_ui (t, n, MPFR_RNDN); - mpfr_div (t, c, t, MPFR_RNDN); /* c/n! */ - mpfr_mul_z (u, t, p, MPFR_RNDN); - mpfr_div_z (s, u, q, MPFR_RNDN); - exps = MPFR_EXP (s); - expU = exps; - for (k = 1; ;k ++) - { - /* update t */ - mpfr_mul (t, t, y, MPFR_RNDN); - mpfr_div_ui (t, t, k, MPFR_RNDN); - mpfr_div_ui (t, t, n + k, MPFR_RNDN); - /* update p/q: - p/q + 1/k + 1/(n+k) = [p*k*(n+k) + q*(n+k) + q*k]/(q*k*(n+k)) */ - mpz_mul_ui (p, p, k); - mpz_mul_ui (p, p, n + k); - mpz_addmul_ui (p, q, n + 2 * k); - mpz_mul_ui (q, q, k); - mpz_mul_ui (q, q, n + k); - mpfr_mul_z (u, t, p, MPFR_RNDN); - mpfr_div_z (u, u, q, MPFR_RNDN); - exps = MPFR_EXP (u); - if (exps > expU) - expU = exps; - mpfr_add (s, s, u, MPFR_RNDN); - exps = MPFR_EXP (s); - if (exps > expU) - expU = exps; - if (MPFR_EXP (u) + (mpfr_exp_t) MPFR_PREC (u) < MPFR_EXP (s) && - zz / (2 * k) < k + n) - break; - } - mpfr_clear (t); - mpfr_clear (u); - mpz_clear (p); - mpz_clear (q); - exps = expU - MPFR_EXP (s); - /* the error is bounded by (6k^2+33/2k+11) 2^exps ulps - <= 8*(k+2)^2 2^exps ulps */ - return 3 + 2 * MPFR_INT_CEIL_LOG2(k + 2) + exps; -} - -int -mpfr_yn (mpfr_ptr res, long n, mpfr_srcptr z, mpfr_rnd_t r) -{ - int inex; - unsigned long absn; - MPFR_SAVE_EXPO_DECL (expo); - - MPFR_LOG_FUNC - (("n=%ld x[%Pu]=%.*Rg rnd=%d", n, mpfr_get_prec (z), mpfr_log_prec, z, r), - ("y[%Pu]=%.*Rg inexact=%d", mpfr_get_prec (res), mpfr_log_prec, res, inex)); - - absn = SAFE_ABS (unsigned long, n); - - if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (z))) - { - if (MPFR_IS_NAN (z)) - { - MPFR_SET_NAN (res); /* y(n,NaN) = NaN */ - MPFR_RET_NAN; - } - /* y(n,z) tends to zero when z goes to +Inf, oscillating around - 0. We choose to return +0 in that case. */ - else if (MPFR_IS_INF (z)) - { - if (MPFR_SIGN(z) > 0) - return mpfr_set_ui (res, 0, r); - else /* y(n,-Inf) = NaN */ - { - MPFR_SET_NAN (res); - MPFR_RET_NAN; - } - } - else /* y(n,z) tends to -Inf for n >= 0 or n even, to +Inf otherwise, - when z goes to zero */ - { - MPFR_SET_INF(res); - if (n >= 0 || ((unsigned long) n & 1) == 0) - MPFR_SET_NEG(res); - else - MPFR_SET_POS(res); - mpfr_set_divby0 (); - MPFR_RET(0); - } - } - - /* for z < 0, y(n,z) is imaginary except when j(n,|z|) = 0, which we - assume does not happen for a rational z. */ - if (MPFR_SIGN(z) < 0) - { - MPFR_SET_NAN (res); - MPFR_RET_NAN; - } - - /* now z is not singular, and z > 0 */ - - MPFR_SAVE_EXPO_MARK (expo); - - /* Deal with tiny arguments. We have: - y0(z) = 2 log(z)/Pi + 2 (euler - log(2))/Pi + O(log(z)*z^2), more - precisely for 0 <= z <= 1/2, with g(z) = 2/Pi + 2(euler-log(2))/Pi/log(z), - g(z) - 0.41*z^2 < y0(z)/log(z) < g(z) - thus since log(z) is negative: - g(z)*log(z) < y0(z) < (g(z) - z^2/2)*log(z) - and since |g(z)| >= 0.63 for 0 <= z <= 1/2, the relative error on - y0(z)/log(z) is bounded by 0.41*z^2/0.63 <= 0.66*z^2. - Note: we use both the main term in log(z) and the constant term, because - otherwise the relative error would be only in 1/log(|log(z)|). - */ - if (n == 0 && MPFR_EXP(z) < - (mpfr_exp_t) (MPFR_PREC(res) / 2)) - { - mpfr_t l, h, t, logz; - mpfr_prec_t prec; - int ok, inex2; - - prec = MPFR_PREC(res) + 10; - mpfr_init2 (l, prec); - mpfr_init2 (h, prec); - mpfr_init2 (t, prec); - mpfr_init2 (logz, prec); - /* first enclose log(z) + euler - log(2) = log(z/2) + euler */ - mpfr_log (logz, z, MPFR_RNDD); /* lower bound of log(z) */ - mpfr_set (h, logz, MPFR_RNDU); /* exact */ - mpfr_nextabove (h); /* upper bound of log(z) */ - mpfr_const_euler (t, MPFR_RNDD); /* lower bound of euler */ - mpfr_add (l, logz, t, MPFR_RNDD); /* lower bound of log(z) + euler */ - mpfr_nextabove (t); /* upper bound of euler */ - mpfr_add (h, h, t, MPFR_RNDU); /* upper bound of log(z) + euler */ - mpfr_const_log2 (t, MPFR_RNDU); /* upper bound of log(2) */ - mpfr_sub (l, l, t, MPFR_RNDD); /* lower bound of log(z/2) + euler */ - mpfr_nextbelow (t); /* lower bound of log(2) */ - mpfr_sub (h, h, t, MPFR_RNDU); /* upper bound of log(z/2) + euler */ - mpfr_const_pi (t, MPFR_RNDU); /* upper bound of Pi */ - mpfr_div (l, l, t, MPFR_RNDD); /* lower bound of (log(z/2)+euler)/Pi */ - mpfr_nextbelow (t); /* lower bound of Pi */ - mpfr_div (h, h, t, MPFR_RNDD); /* upper bound of (log(z/2)+euler)/Pi */ - mpfr_mul_2ui (l, l, 1, MPFR_RNDD); /* lower bound on g(z)*log(z) */ - mpfr_mul_2ui (h, h, 1, MPFR_RNDU); /* upper bound on g(z)*log(z) */ - /* we now have l <= g(z)*log(z) <= h, and we need to add -z^2/2*log(z) - to h */ - mpfr_mul (t, z, z, MPFR_RNDU); /* upper bound on z^2 */ - /* since logz is negative, a lower bound corresponds to an upper bound - for its absolute value */ - mpfr_neg (t, t, MPFR_RNDD); - mpfr_div_2ui (t, t, 1, MPFR_RNDD); - mpfr_mul (t, t, logz, MPFR_RNDU); /* upper bound on z^2/2*log(z) */ - mpfr_add (h, h, t, MPFR_RNDU); - inex = mpfr_prec_round (l, MPFR_PREC(res), r); - inex2 = mpfr_prec_round (h, MPFR_PREC(res), r); - /* we need h=l and inex=inex2 */ - ok = (inex == inex2) && mpfr_equal_p (l, h); - if (ok) - mpfr_set (res, h, r); /* exact */ - mpfr_clear (l); - mpfr_clear (h); - mpfr_clear (t); - mpfr_clear (logz); - if (ok) - goto end; - } - - /* small argument check for y1(z) = -2/Pi/z + O(log(z)): - for 0 <= z <= 1, |y1(z) + 2/Pi/z| <= 0.25 */ - if (n == 1 && MPFR_EXP(z) + 1 < - (mpfr_exp_t) MPFR_PREC(res)) - { - mpfr_t y; - mpfr_prec_t prec; - mpfr_exp_t err1; - int ok; - MPFR_BLOCK_DECL (flags); - - /* since 2/Pi > 0.5, and |y1(z)| >= |2/Pi/z|, if z <= 2^(-emax-1), - then |y1(z)| > 2^emax */ - prec = MPFR_PREC(res) + 10; - mpfr_init2 (y, prec); - mpfr_const_pi (y, MPFR_RNDU); /* Pi*(1+u)^2, where here and below u - represents a quantity <= 1/2^prec */ - mpfr_mul (y, y, z, MPFR_RNDU); /* Pi*z * (1+u)^4, upper bound */ - MPFR_BLOCK (flags, mpfr_ui_div (y, 2, y, MPFR_RNDZ)); - /* 2/Pi/z * (1+u)^6, lower bound, with possible overflow */ - if (MPFR_OVERFLOW (flags)) - { - mpfr_clear (y); - MPFR_SAVE_EXPO_FREE (expo); - return mpfr_overflow (res, r, -1); - } - mpfr_neg (y, y, MPFR_RNDN); - /* (1+u)^6 can be written 1+7u [for another value of u], thus the - error on 2/Pi/z is less than 7ulp(y). The truncation error is less - than 1/4, thus if ulp(y)>=1/4, the total error is less than 8ulp(y), - otherwise it is less than 1/4+7/8 <= 2. */ - if (MPFR_EXP(y) + 2 >= MPFR_PREC(y)) /* ulp(y) >= 1/4 */ - err1 = 3; - else /* ulp(y) <= 1/8 */ - err1 = (mpfr_exp_t) MPFR_PREC(y) - MPFR_EXP(y) + 1; - ok = MPFR_CAN_ROUND (y, prec - err1, MPFR_PREC(res), r); - if (ok) - inex = mpfr_set (res, y, r); - mpfr_clear (y); - if (ok) - goto end; - } - - /* we can use the asymptotic expansion as soon as z > p log(2)/2, - but to get some margin we use it for z > p/2 */ - if (mpfr_cmp_ui (z, MPFR_PREC(res) / 2 + 3) > 0) - { - inex = mpfr_yn_asympt (res, n, z, r); - if (inex != 0) - goto end; - } - - /* General case */ - { - mpfr_prec_t prec; - mpfr_exp_t err1, err2, err3; - mpfr_t y, s1, s2, s3; - MPFR_ZIV_DECL (loop); - - mpfr_init (y); - mpfr_init (s1); - mpfr_init (s2); - mpfr_init (s3); - - prec = MPFR_PREC(res) + 2 * MPFR_INT_CEIL_LOG2 (MPFR_PREC (res)) + 13; - MPFR_ZIV_INIT (loop, prec); - for (;;) - { - mpfr_set_prec (y, prec); - mpfr_set_prec (s1, prec); - mpfr_set_prec (s2, prec); - mpfr_set_prec (s3, prec); - - mpfr_mul (y, z, z, MPFR_RNDN); - mpfr_div_2ui (y, y, 2, MPFR_RNDN); /* z^2/4 */ - - /* store (z/2)^n temporarily in s2 */ - mpfr_pow_ui (s2, z, absn, MPFR_RNDN); - mpfr_div_2si (s2, s2, absn, MPFR_RNDN); - - /* compute S1 * (z/2)^(-n) */ - if (n == 0) - { - mpfr_set_ui (s1, 0, MPFR_RNDN); - err1 = 0; - } - else - err1 = mpfr_yn_s1 (s1, y, absn - 1); - mpfr_div (s1, s1, s2, MPFR_RNDN); /* (z/2)^(-n) * S1 */ - /* See algorithms.tex: the relative error on s1 is bounded by - (3n+3)*2^(e+1-prec). */ - err1 = MPFR_INT_CEIL_LOG2 (3 * absn + 3) + err1 + 1; - /* rel_err(s1) <= 2^(err1-prec), thus err(s1) <= 2^err1 ulps */ - - /* compute (z/2)^n * S3 */ - mpfr_neg (y, y, MPFR_RNDN); /* -z^2/4 */ - err3 = mpfr_yn_s3 (s3, y, s2, absn); /* (z/2)^n * S3 */ - /* the error on s3 is bounded by 2^err3 ulps */ - - /* add s1+s3 */ - err1 += MPFR_EXP(s1); - mpfr_add (s1, s1, s3, MPFR_RNDN); - /* the error is bounded by 1/2 + 2^err1*2^(- EXP(s1)) - + 2^err3*2^(EXP(s3) - EXP(s1)) */ - err3 += MPFR_EXP(s3); - err1 = (err3 > err1) ? err3 + 1 : err1 + 1; - err1 -= MPFR_EXP(s1); - err1 = (err1 >= 0) ? err1 + 1 : 1; - /* now the error on s1 is bounded by 2^err1*ulp(s1) */ - - /* compute S2 */ - mpfr_div_2ui (s2, z, 1, MPFR_RNDN); /* z/2 */ - mpfr_log (s2, s2, MPFR_RNDN); /* log(z/2) */ - mpfr_const_euler (s3, MPFR_RNDN); - err2 = MPFR_EXP(s2) > MPFR_EXP(s3) ? MPFR_EXP(s2) : MPFR_EXP(s3); - mpfr_add (s2, s2, s3, MPFR_RNDN); /* log(z/2) + gamma */ - err2 -= MPFR_EXP(s2); - mpfr_mul_2ui (s2, s2, 1, MPFR_RNDN); /* 2*(log(z/2) + gamma) */ - mpfr_jn (s3, absn, z, MPFR_RNDN); /* Jn(z) */ - mpfr_mul (s2, s2, s3, MPFR_RNDN); /* 2*(log(z/2) + gamma)*Jn(z) */ - err2 += 4; /* the error on s2 is bounded by 2^err2 ulps, see - algorithms.tex */ - - /* add all three sums */ - err1 += MPFR_EXP(s1); /* the error on s1 is bounded by 2^err1 */ - err2 += MPFR_EXP(s2); /* the error on s2 is bounded by 2^err2 */ - mpfr_sub (s2, s2, s1, MPFR_RNDN); /* s2 - (s1+s3) */ - err2 = (err1 > err2) ? err1 + 1 : err2 + 1; - err2 -= MPFR_EXP(s2); - err2 = (err2 >= 0) ? err2 + 1 : 1; - /* now the error on s2 is bounded by 2^err2*ulp(s2) */ - mpfr_const_pi (y, MPFR_RNDN); /* error bounded by 1 ulp */ - mpfr_div (s2, s2, y, MPFR_RNDN); /* error bounded by - 2^(err2+1)*ulp(s2) */ - err2 ++; - - if (MPFR_LIKELY (MPFR_CAN_ROUND (s2, prec - err2, MPFR_PREC(res), r))) - break; - MPFR_ZIV_NEXT (loop, prec); - } - MPFR_ZIV_FREE (loop); - - /* Assume two's complement for the test n & 1 */ - inex = mpfr_set4 (res, s2, r, n >= 0 || (n & 1) == 0 ? - MPFR_SIGN (s2) : - MPFR_SIGN (s2)); - - mpfr_clear (y); - mpfr_clear (s1); - mpfr_clear (s2); - mpfr_clear (s3); - } - - end: - MPFR_SAVE_EXPO_FREE (expo); - return mpfr_check_range (res, inex, r); -} - -#define MPFR_YN -#include "jyn_asympt.c" |