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Diffstat (limited to 'gsl-1.9/specfunc/zeta.c')
-rw-r--r-- | gsl-1.9/specfunc/zeta.c | 1050 |
1 files changed, 1050 insertions, 0 deletions
diff --git a/gsl-1.9/specfunc/zeta.c b/gsl-1.9/specfunc/zeta.c new file mode 100644 index 0000000..078d7d3 --- /dev/null +++ b/gsl-1.9/specfunc/zeta.c @@ -0,0 +1,1050 @@ +/* specfunc/zeta.c + * + * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2004 Gerard Jungman + * + * This program 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. + * + * This program 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 this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +/* Author: G. Jungman */ + +#include <config.h> +#include <gsl/gsl_math.h> +#include <gsl/gsl_errno.h> +#include <gsl/gsl_sf_elementary.h> +#include <gsl/gsl_sf_exp.h> +#include <gsl/gsl_sf_gamma.h> +#include <gsl/gsl_sf_pow_int.h> +#include <gsl/gsl_sf_zeta.h> + +#include "error.h" + +#include "chebyshev.h" +#include "cheb_eval.c" + +#define LogTwoPi_ 1.8378770664093454835606594728111235279723 + + +/*-*-*-*-*-*-*-*-*-*-*-* Private Section *-*-*-*-*-*-*-*-*-*-*-*/ + +/* chebyshev fit for (s(t)-1)Zeta[s(t)] + * s(t)= (t+1)/2 + * -1 <= t <= 1 + */ +static double zeta_xlt1_data[14] = { + 1.48018677156931561235192914649, + 0.25012062539889426471999938167, + 0.00991137502135360774243761467, + -0.00012084759656676410329833091, + -4.7585866367662556504652535281e-06, + 2.2229946694466391855561441361e-07, + -2.2237496498030257121309056582e-09, + -1.0173226513229028319420799028e-10, + 4.3756643450424558284466248449e-12, + -6.2229632593100551465504090814e-14, + -6.6116201003272207115277520305e-16, + 4.9477279533373912324518463830e-17, + -1.0429819093456189719660003522e-18, + 6.9925216166580021051464412040e-21, +}; +static cheb_series zeta_xlt1_cs = { + zeta_xlt1_data, + 13, + -1, 1, + 8 +}; + +/* chebyshev fit for (s(t)-1)Zeta[s(t)] + * s(t)= (19t+21)/2 + * -1 <= t <= 1 + */ +static double zeta_xgt1_data[30] = { + 19.3918515726724119415911269006, + 9.1525329692510756181581271500, + 0.2427897658867379985365270155, + -0.1339000688262027338316641329, + 0.0577827064065028595578410202, + -0.0187625983754002298566409700, + 0.0039403014258320354840823803, + -0.0000581508273158127963598882, + -0.0003756148907214820704594549, + 0.0001892530548109214349092999, + -0.0000549032199695513496115090, + 8.7086484008939038610413331863e-6, + 6.4609477924811889068410083425e-7, + -9.6749773915059089205835337136e-7, + 3.6585400766767257736982342461e-7, + -8.4592516427275164351876072573e-8, + 9.9956786144497936572288988883e-9, + 1.4260036420951118112457144842e-9, + -1.1761968823382879195380320948e-9, + 3.7114575899785204664648987295e-10, + -7.4756855194210961661210215325e-11, + 7.8536934209183700456512982968e-12, + 9.9827182259685539619810406271e-13, + -7.5276687030192221587850302453e-13, + 2.1955026393964279988917878654e-13, + -4.1934859852834647427576319246e-14, + 4.6341149635933550715779074274e-15, + 2.3742488509048340106830309402e-16, + -2.7276516388124786119323824391e-16, + 7.8473570134636044722154797225e-17 +}; +static cheb_series zeta_xgt1_cs = { + zeta_xgt1_data, + 29, + -1, 1, + 17 +}; + + +/* chebyshev fit for Ln[Zeta[s(t)] - 1 - 2^(-s(t))] + * s(t)= 10 + 5t + * -1 <= t <= 1; 5 <= s <= 15 + */ +static double zetam1_inter_data[24] = { + -21.7509435653088483422022339374, + -5.63036877698121782876372020472, + 0.0528041358684229425504861579635, + -0.0156381809179670789342700883562, + 0.00408218474372355881195080781927, + -0.0010264867349474874045036628282, + 0.000260469880409886900143834962387, + -0.0000676175847209968878098566819447, + 0.0000179284472587833525426660171124, + -4.83238651318556188834107605116e-6, + 1.31913788964999288471371329447e-6, + -3.63760500656329972578222188542e-7, + 1.01146847513194744989748396574e-7, + -2.83215225141806501619105289509e-8, + 7.97733710252021423361012829496e-9, + -2.25850168553956886676250696891e-9, + 6.42269392950164306086395744145e-10, + -1.83363861846127284505060843614e-10, + 5.25309763895283179960368072104e-11, + -1.50958687042589821074710575446e-11, + 4.34997545516049244697776942981e-12, + -1.25597782748190416118082322061e-12, + 3.61280740072222650030134104162e-13, + -9.66437239205745207188920348801e-14 +}; +static cheb_series zetam1_inter_cs = { + zetam1_inter_data, + 22, + -1, 1, + 12 +}; + + + +/* assumes s >= 0 and s != 1.0 */ +inline +static int +riemann_zeta_sgt0(double s, gsl_sf_result * result) +{ + if(s < 1.0) { + gsl_sf_result c; + cheb_eval_e(&zeta_xlt1_cs, 2.0*s - 1.0, &c); + result->val = c.val / (s - 1.0); + result->err = c.err / fabs(s-1.0) + GSL_DBL_EPSILON * fabs(result->val); + return GSL_SUCCESS; + } + else if(s <= 20.0) { + double x = (2.0*s - 21.0)/19.0; + gsl_sf_result c; + cheb_eval_e(&zeta_xgt1_cs, x, &c); + result->val = c.val / (s - 1.0); + result->err = c.err / (s - 1.0) + GSL_DBL_EPSILON * fabs(result->val); + return GSL_SUCCESS; + } + else { + double f2 = 1.0 - pow(2.0,-s); + double f3 = 1.0 - pow(3.0,-s); + double f5 = 1.0 - pow(5.0,-s); + double f7 = 1.0 - pow(7.0,-s); + result->val = 1.0/(f2*f3*f5*f7); + result->err = 3.0 * GSL_DBL_EPSILON * fabs(result->val); + return GSL_SUCCESS; + } +} + + +inline +static int +riemann_zeta1ms_slt0(double s, gsl_sf_result * result) +{ + if(s > -19.0) { + double x = (-19 - 2.0*s)/19.0; + gsl_sf_result c; + cheb_eval_e(&zeta_xgt1_cs, x, &c); + result->val = c.val / (-s); + result->err = c.err / (-s) + GSL_DBL_EPSILON * fabs(result->val); + return GSL_SUCCESS; + } + else { + double f2 = 1.0 - pow(2.0,-(1.0-s)); + double f3 = 1.0 - pow(3.0,-(1.0-s)); + double f5 = 1.0 - pow(5.0,-(1.0-s)); + double f7 = 1.0 - pow(7.0,-(1.0-s)); + result->val = 1.0/(f2*f3*f5*f7); + result->err = 3.0 * GSL_DBL_EPSILON * fabs(result->val); + return GSL_SUCCESS; + } +} + + +/* works for 5 < s < 15*/ +static int +riemann_zeta_minus_1_intermediate_s(double s, gsl_sf_result * result) +{ + double t = (s - 10.0)/5.0; + gsl_sf_result c; + cheb_eval_e(&zetam1_inter_cs, t, &c); + result->val = exp(c.val) + pow(2.0, -s); + result->err = (c.err + 2.0*GSL_DBL_EPSILON)*result->val; + return GSL_SUCCESS; +} + + +/* assumes s is large and positive + * write: zeta(s) - 1 = zeta(s) * (1 - 1/zeta(s)) + * and expand a few terms of the product formula to evaluate 1 - 1/zeta(s) + * + * works well for s > 15 + */ +static int +riemann_zeta_minus1_large_s(double s, gsl_sf_result * result) +{ + double a = pow( 2.0,-s); + double b = pow( 3.0,-s); + double c = pow( 5.0,-s); + double d = pow( 7.0,-s); + double e = pow(11.0,-s); + double f = pow(13.0,-s); + double t1 = a + b + c + d + e + f; + double t2 = a*(b+c+d+e+f) + b*(c+d+e+f) + c*(d+e+f) + d*(e+f) + e*f; + /* + double t3 = a*(b*(c+d+e+f) + c*(d+e+f) + d*(e+f) + e*f) + + b*(c*(d+e+f) + d*(e+f) + e*f) + + c*(d*(e+f) + e*f) + + d*e*f; + double t4 = a*(b*(c*(d + e + f) + d*(e + f) + e*f) + c*(d*(e+f) + e*f) + d*e*f) + + b*(c*(d*(e+f) + e*f) + d*e*f) + + c*d*e*f; + double t5 = b*c*d*e*f + a*c*d*e*f+ a*b*d*e*f+ a*b*c*e*f+ a*b*c*d*f+ a*b*c*d*e; + double t6 = a*b*c*d*e*f; + */ + double numt = t1 - t2 /* + t3 - t4 + t5 - t6 */; + double zeta = 1.0/((1.0-a)*(1.0-b)*(1.0-c)*(1.0-d)*(1.0-e)*(1.0-f)); + result->val = numt*zeta; + result->err = (15.0/s + 1.0) * 6.0*GSL_DBL_EPSILON*result->val; + return GSL_SUCCESS; +} + + +#if 0 +/* zeta(n) */ +#define ZETA_POS_TABLE_NMAX 100 +static double zeta_pos_int_table_OLD[ZETA_POS_TABLE_NMAX+1] = { + -0.50000000000000000000000000000, /* zeta(0) */ + 0.0 /* FIXME: DirectedInfinity() */, /* zeta(1) */ + 1.64493406684822643647241516665, /* ... */ + 1.20205690315959428539973816151, + 1.08232323371113819151600369654, + 1.03692775514336992633136548646, + 1.01734306198444913971451792979, + 1.00834927738192282683979754985, + 1.00407735619794433937868523851, + 1.00200839282608221441785276923, + 1.00099457512781808533714595890, + 1.00049418860411946455870228253, + 1.00024608655330804829863799805, + 1.00012271334757848914675183653, + 1.00006124813505870482925854511, + 1.00003058823630702049355172851, + 1.00001528225940865187173257149, + 1.00000763719763789976227360029, + 1.00000381729326499983985646164, + 1.00000190821271655393892565696, + 1.00000095396203387279611315204, + 1.00000047693298678780646311672, + 1.00000023845050272773299000365, + 1.00000011921992596531107306779, + 1.00000005960818905125947961244, + 1.00000002980350351465228018606, + 1.00000001490155482836504123466, + 1.00000000745071178983542949198, + 1.00000000372533402478845705482, + 1.00000000186265972351304900640, + 1.00000000093132743241966818287, + 1.00000000046566290650337840730, + 1.00000000023283118336765054920, + 1.00000000011641550172700519776, + 1.00000000005820772087902700889, + 1.00000000002910385044497099687, + 1.00000000001455192189104198424, + 1.00000000000727595983505748101, + 1.00000000000363797954737865119, + 1.00000000000181898965030706595, + 1.00000000000090949478402638893, + 1.00000000000045474737830421540, + 1.00000000000022737368458246525, + 1.00000000000011368684076802278, + 1.00000000000005684341987627586, + 1.00000000000002842170976889302, + 1.00000000000001421085482803161, + 1.00000000000000710542739521085, + 1.00000000000000355271369133711, + 1.00000000000000177635684357912, + 1.00000000000000088817842109308, + 1.00000000000000044408921031438, + 1.00000000000000022204460507980, + 1.00000000000000011102230251411, + 1.00000000000000005551115124845, + 1.00000000000000002775557562136, + 1.00000000000000001387778780973, + 1.00000000000000000693889390454, + 1.00000000000000000346944695217, + 1.00000000000000000173472347605, + 1.00000000000000000086736173801, + 1.00000000000000000043368086900, + 1.00000000000000000021684043450, + 1.00000000000000000010842021725, + 1.00000000000000000005421010862, + 1.00000000000000000002710505431, + 1.00000000000000000001355252716, + 1.00000000000000000000677626358, + 1.00000000000000000000338813179, + 1.00000000000000000000169406589, + 1.00000000000000000000084703295, + 1.00000000000000000000042351647, + 1.00000000000000000000021175824, + 1.00000000000000000000010587912, + 1.00000000000000000000005293956, + 1.00000000000000000000002646978, + 1.00000000000000000000001323489, + 1.00000000000000000000000661744, + 1.00000000000000000000000330872, + 1.00000000000000000000000165436, + 1.00000000000000000000000082718, + 1.00000000000000000000000041359, + 1.00000000000000000000000020680, + 1.00000000000000000000000010340, + 1.00000000000000000000000005170, + 1.00000000000000000000000002585, + 1.00000000000000000000000001292, + 1.00000000000000000000000000646, + 1.00000000000000000000000000323, + 1.00000000000000000000000000162, + 1.00000000000000000000000000081, + 1.00000000000000000000000000040, + 1.00000000000000000000000000020, + 1.00000000000000000000000000010, + 1.00000000000000000000000000005, + 1.00000000000000000000000000003, + 1.00000000000000000000000000001, + 1.00000000000000000000000000001, + 1.00000000000000000000000000000, + 1.00000000000000000000000000000, + 1.00000000000000000000000000000 +}; +#endif /* 0 */ + + +/* zeta(n) - 1 */ +#define ZETA_POS_TABLE_NMAX 100 +static double zetam1_pos_int_table[ZETA_POS_TABLE_NMAX+1] = { + -1.5, /* zeta(0) */ + 0.0, /* FIXME: Infinity */ /* zeta(1) - 1 */ + 0.644934066848226436472415166646, /* zeta(2) - 1 */ + 0.202056903159594285399738161511, + 0.082323233711138191516003696541, + 0.036927755143369926331365486457, + 0.017343061984449139714517929790, + 0.008349277381922826839797549849, + 0.004077356197944339378685238508, + 0.002008392826082214417852769232, + 0.000994575127818085337145958900, + 0.000494188604119464558702282526, + 0.000246086553308048298637998047, + 0.000122713347578489146751836526, + 0.000061248135058704829258545105, + 0.000030588236307020493551728510, + 0.000015282259408651871732571487, + 7.6371976378997622736002935630e-6, + 3.8172932649998398564616446219e-6, + 1.9082127165539389256569577951e-6, + 9.5396203387279611315203868344e-7, + 4.7693298678780646311671960437e-7, + 2.3845050272773299000364818675e-7, + 1.1921992596531107306778871888e-7, + 5.9608189051259479612440207935e-8, + 2.9803503514652280186063705069e-8, + 1.4901554828365041234658506630e-8, + 7.4507117898354294919810041706e-9, + 3.7253340247884570548192040184e-9, + 1.8626597235130490064039099454e-9, + 9.3132743241966818287176473502e-10, + 4.6566290650337840729892332512e-10, + 2.3283118336765054920014559759e-10, + 1.1641550172700519775929738354e-10, + 5.8207720879027008892436859891e-11, + 2.9103850444970996869294252278e-11, + 1.4551921891041984235929632245e-11, + 7.2759598350574810145208690123e-12, + 3.6379795473786511902372363558e-12, + 1.8189896503070659475848321007e-12, + 9.0949478402638892825331183869e-13, + 4.5474737830421540267991120294e-13, + 2.2737368458246525152268215779e-13, + 1.1368684076802278493491048380e-13, + 5.6843419876275856092771829675e-14, + 2.8421709768893018554550737049e-14, + 1.4210854828031606769834307141e-14, + 7.1054273952108527128773544799e-15, + 3.5527136913371136732984695340e-15, + 1.7763568435791203274733490144e-15, + 8.8817842109308159030960913863e-16, + 4.4408921031438133641977709402e-16, + 2.2204460507980419839993200942e-16, + 1.1102230251410661337205445699e-16, + 5.5511151248454812437237365905e-17, + 2.7755575621361241725816324538e-17, + 1.3877787809725232762839094906e-17, + 6.9388939045441536974460853262e-18, + 3.4694469521659226247442714961e-18, + 1.7347234760475765720489729699e-18, + 8.6736173801199337283420550673e-19, + 4.3368086900206504874970235659e-19, + 2.1684043449972197850139101683e-19, + 1.0842021724942414063012711165e-19, + 5.4210108624566454109187004043e-20, + 2.7105054312234688319546213119e-20, + 1.3552527156101164581485233996e-20, + 6.7762635780451890979952987415e-21, + 3.3881317890207968180857031004e-21, + 1.6940658945097991654064927471e-21, + 8.4703294725469983482469926091e-22, + 4.2351647362728333478622704833e-22, + 2.1175823681361947318442094398e-22, + 1.0587911840680233852265001539e-22, + 5.2939559203398703238139123029e-23, + 2.6469779601698529611341166842e-23, + 1.3234889800848990803094510250e-23, + 6.6174449004244040673552453323e-24, + 3.3087224502121715889469563843e-24, + 1.6543612251060756462299236771e-24, + 8.2718061255303444036711056167e-25, + 4.1359030627651609260093824555e-25, + 2.0679515313825767043959679193e-25, + 1.0339757656912870993284095591e-25, + 5.1698788284564313204101332166e-26, + 2.5849394142282142681277617708e-26, + 1.2924697071141066700381126118e-26, + 6.4623485355705318034380021611e-27, + 3.2311742677852653861348141180e-27, + 1.6155871338926325212060114057e-27, + 8.0779356694631620331587381863e-28, + 4.0389678347315808256222628129e-28, + 2.0194839173657903491587626465e-28, + 1.0097419586828951533619250700e-28, + 5.0487097934144756960847711725e-29, + 2.5243548967072378244674341938e-29, + 1.2621774483536189043753999660e-29, + 6.3108872417680944956826093943e-30, + 3.1554436208840472391098412184e-30, + 1.5777218104420236166444327830e-30, + 7.8886090522101180735205378276e-31 +}; + + +#define ZETA_NEG_TABLE_NMAX 99 +#define ZETA_NEG_TABLE_SIZE 50 +static double zeta_neg_int_table[ZETA_NEG_TABLE_SIZE] = { + -0.083333333333333333333333333333, /* zeta(-1) */ + 0.008333333333333333333333333333, /* zeta(-3) */ + -0.003968253968253968253968253968, /* ... */ + 0.004166666666666666666666666667, + -0.007575757575757575757575757576, + 0.021092796092796092796092796093, + -0.083333333333333333333333333333, + 0.44325980392156862745098039216, + -3.05395433027011974380395433027, + 26.4562121212121212121212121212, + -281.460144927536231884057971014, + 3607.5105463980463980463980464, + -54827.583333333333333333333333, + 974936.82385057471264367816092, + -2.0052695796688078946143462272e+07, + 4.7238486772162990196078431373e+08, + -1.2635724795916666666666666667e+10, + 3.8087931125245368811553022079e+11, + -1.2850850499305083333333333333e+13, + 4.8241448354850170371581670362e+14, + -2.0040310656516252738108421663e+16, + 9.1677436031953307756992753623e+17, + -4.5979888343656503490437943262e+19, + 2.5180471921451095697089023320e+21, + -1.5001733492153928733711440151e+23, + 9.6899578874635940656497942895e+24, + -6.7645882379292820990945242302e+26, + 5.0890659468662289689766332916e+28, + -4.1147288792557978697665486068e+30, + 3.5666582095375556109684574609e+32, + -3.3066089876577576725680214670e+34, + 3.2715634236478716264211227016e+36, + -3.4473782558278053878256455080e+38, + 3.8614279832705258893092720200e+40, + -4.5892974432454332168863989006e+42, + 5.7775386342770431824884825688e+44, + -7.6919858759507135167410075972e+46, + 1.0813635449971654696354033351e+49, + -1.6029364522008965406067102346e+51, + 2.5019479041560462843656661499e+53, + -4.1067052335810212479752045004e+55, + 7.0798774408494580617452972433e+57, + -1.2804546887939508790190849756e+60, + 2.4267340392333524078020892067e+62, + -4.8143218874045769355129570066e+64, + 9.9875574175727530680652777408e+66, + -2.1645634868435185631335136160e+69, + 4.8962327039620553206849224516e+71, /* ... */ + -1.1549023923963519663954271692e+74, /* zeta(-97) */ + 2.8382249570693706959264156336e+76 /* zeta(-99) */ +}; + + +/* coefficients for Maclaurin summation in hzeta() + * B_{2j}/(2j)! + */ +static double hzeta_c[15] = { + 1.00000000000000000000000000000, + 0.083333333333333333333333333333, + -0.00138888888888888888888888888889, + 0.000033068783068783068783068783069, + -8.2671957671957671957671957672e-07, + 2.0876756987868098979210090321e-08, + -5.2841901386874931848476822022e-10, + 1.3382536530684678832826980975e-11, + -3.3896802963225828668301953912e-13, + 8.5860620562778445641359054504e-15, + -2.1748686985580618730415164239e-16, + 5.5090028283602295152026526089e-18, + -1.3954464685812523340707686264e-19, + 3.5347070396294674716932299778e-21, + -8.9535174270375468504026113181e-23 +}; + +#define ETA_POS_TABLE_NMAX 100 +static double eta_pos_int_table[ETA_POS_TABLE_NMAX+1] = { +0.50000000000000000000000000000, /* eta(0) */ +M_LN2, /* eta(1) */ +0.82246703342411321823620758332, /* ... */ +0.90154267736969571404980362113, +0.94703282949724591757650323447, +0.97211977044690930593565514355, +0.98555109129743510409843924448, +0.99259381992283028267042571313, +0.99623300185264789922728926008, +0.99809429754160533076778303185, +0.99903950759827156563922184570, +0.99951714349806075414409417483, +0.99975768514385819085317967871, +0.99987854276326511549217499282, +0.99993917034597971817095419226, +0.99996955121309923808263293263, +0.99998476421490610644168277496, +0.99999237829204101197693787224, +0.99999618786961011347968922641, +0.99999809350817167510685649297, +0.99999904661158152211505084256, +0.99999952325821554281631666433, +0.99999976161323082254789720494, +0.99999988080131843950322382485, +0.99999994039889239462836140314, +0.99999997019885696283441513311, +0.99999998509923199656878766181, +0.99999999254955048496351585274, +0.99999999627475340010872752767, +0.99999999813736941811218674656, +0.99999999906868228145397862728, +0.99999999953434033145421751469, +0.99999999976716989595149082282, +0.99999999988358485804603047265, +0.99999999994179239904531592388, +0.99999999997089618952980952258, +0.99999999998544809143388476396, +0.99999999999272404460658475006, +0.99999999999636202193316875550, +0.99999999999818101084320873555, +0.99999999999909050538047887809, +0.99999999999954525267653087357, +0.99999999999977262633369589773, +0.99999999999988631316532476488, +0.99999999999994315658215465336, +0.99999999999997157829090808339, +0.99999999999998578914539762720, +0.99999999999999289457268000875, +0.99999999999999644728633373609, +0.99999999999999822364316477861, +0.99999999999999911182158169283, +0.99999999999999955591079061426, +0.99999999999999977795539522974, +0.99999999999999988897769758908, +0.99999999999999994448884878594, +0.99999999999999997224442439010, +0.99999999999999998612221219410, +0.99999999999999999306110609673, +0.99999999999999999653055304826, +0.99999999999999999826527652409, +0.99999999999999999913263826204, +0.99999999999999999956631913101, +0.99999999999999999978315956551, +0.99999999999999999989157978275, +0.99999999999999999994578989138, +0.99999999999999999997289494569, +0.99999999999999999998644747284, +0.99999999999999999999322373642, +0.99999999999999999999661186821, +0.99999999999999999999830593411, +0.99999999999999999999915296705, +0.99999999999999999999957648353, +0.99999999999999999999978824176, +0.99999999999999999999989412088, +0.99999999999999999999994706044, +0.99999999999999999999997353022, +0.99999999999999999999998676511, +0.99999999999999999999999338256, +0.99999999999999999999999669128, +0.99999999999999999999999834564, +0.99999999999999999999999917282, +0.99999999999999999999999958641, +0.99999999999999999999999979320, +0.99999999999999999999999989660, +0.99999999999999999999999994830, +0.99999999999999999999999997415, +0.99999999999999999999999998708, +0.99999999999999999999999999354, +0.99999999999999999999999999677, +0.99999999999999999999999999838, +0.99999999999999999999999999919, +0.99999999999999999999999999960, +0.99999999999999999999999999980, +0.99999999999999999999999999990, +0.99999999999999999999999999995, +0.99999999999999999999999999997, +0.99999999999999999999999999999, +0.99999999999999999999999999999, +1.00000000000000000000000000000, +1.00000000000000000000000000000, +1.00000000000000000000000000000, +}; + + +#define ETA_NEG_TABLE_NMAX 99 +#define ETA_NEG_TABLE_SIZE 50 +static double eta_neg_int_table[ETA_NEG_TABLE_SIZE] = { + 0.25000000000000000000000000000, /* eta(-1) */ +-0.12500000000000000000000000000, /* eta(-3) */ + 0.25000000000000000000000000000, /* ... */ +-1.06250000000000000000000000000, + 7.75000000000000000000000000000, +-86.3750000000000000000000000000, + 1365.25000000000000000000000000, +-29049.0312500000000000000000000, + 800572.750000000000000000000000, +-2.7741322625000000000000000000e+7, + 1.1805291302500000000000000000e+9, +-6.0523980051687500000000000000e+10, + 3.6794167785377500000000000000e+12, +-2.6170760990658387500000000000e+14, + 2.1531418140800295250000000000e+16, +-2.0288775575173015930156250000e+18, + 2.1708009902623770590275000000e+20, +-2.6173826968455814932120125000e+22, + 3.5324148876863877826668602500e+24, +-5.3042033406864906641493838981e+26, + 8.8138218364311576767253114668e+28, +-1.6128065107490778547354654864e+31, + 3.2355470001722734208527794569e+33, +-7.0876727476537493198506645215e+35, + 1.6890450341293965779175629389e+38, +-4.3639690731216831157655651358e+40, + 1.2185998827061261322605065672e+43, +-3.6670584803153006180101262324e+45, + 1.1859898526302099104271449748e+48, +-4.1120769493584015047981746438e+50, + 1.5249042436787620309090168687e+53, +-6.0349693196941307074572991901e+55, + 2.5437161764210695823197691519e+58, +-1.1396923802632287851130360170e+61, + 5.4180861064753979196802726455e+63, +-2.7283654799994373847287197104e+66, + 1.4529750514918543238511171663e+69, +-8.1705519371067450079777183386e+71, + 4.8445781606678367790247757259e+74, +-3.0246694206649519336179448018e+77, + 1.9858807961690493054169047970e+80, +-1.3694474620720086994386818232e+83, + 9.9070382984295807826303785989e+85, +-7.5103780796592645925968460677e+88, + 5.9598418264260880840077992227e+91, +-4.9455988887500020399263196307e+94, + 4.2873596927020241277675775935e+97, +-3.8791952037716162900707994047e+100, + 3.6600317773156342245401829308e+103, +-3.5978775704117283875784869570e+106 /* eta(-99) */ +}; + + +/*-*-*-*-*-*-*-*-*-*-*-* Functions with Error Codes *-*-*-*-*-*-*-*-*-*-*-*/ + + +int gsl_sf_hzeta_e(const double s, const double q, gsl_sf_result * result) +{ + /* CHECK_POINTER(result) */ + + if(s <= 1.0 || q <= 0.0) { + DOMAIN_ERROR(result); + } + else { + const double max_bits = 54.0; + const double ln_term0 = -s * log(q); + + if(ln_term0 < GSL_LOG_DBL_MIN + 1.0) { + UNDERFLOW_ERROR(result); + } + else if(ln_term0 > GSL_LOG_DBL_MAX - 1.0) { + OVERFLOW_ERROR (result); + } + else if((s > max_bits && q < 1.0) || (s > 0.5*max_bits && q < 0.25)) { + result->val = pow(q, -s); + result->err = 2.0 * GSL_DBL_EPSILON * fabs(result->val); + return GSL_SUCCESS; + } + else if(s > 0.5*max_bits && q < 1.0) { + const double p1 = pow(q, -s); + const double p2 = pow(q/(1.0+q), s); + const double p3 = pow(q/(2.0+q), s); + result->val = p1 * (1.0 + p2 + p3); + result->err = GSL_DBL_EPSILON * (0.5*s + 2.0) * fabs(result->val); + return GSL_SUCCESS; + } + else { + /* Euler-Maclaurin summation formula + * [Moshier, p. 400, with several typo corrections] + */ + const int jmax = 12; + const int kmax = 10; + int j, k; + const double pmax = pow(kmax + q, -s); + double scp = s; + double pcp = pmax / (kmax + q); + double ans = pmax*((kmax+q)/(s-1.0) + 0.5); + + for(k=0; k<kmax; k++) { + ans += pow(k + q, -s); + } + + for(j=0; j<=jmax; j++) { + double delta = hzeta_c[j+1] * scp * pcp; + ans += delta; + if(fabs(delta/ans) < 0.5*GSL_DBL_EPSILON) break; + scp *= (s+2*j+1)*(s+2*j+2); + pcp /= (kmax + q)*(kmax + q); + } + + result->val = ans; + result->err = 2.0 * (jmax + 1.0) * GSL_DBL_EPSILON * fabs(ans); + return GSL_SUCCESS; + } + } +} + + +int gsl_sf_zeta_e(const double s, gsl_sf_result * result) +{ + /* CHECK_POINTER(result) */ + + if(s == 1.0) { + DOMAIN_ERROR(result); + } + else if(s >= 0.0) { + return riemann_zeta_sgt0(s, result); + } + else { + /* reflection formula, [Abramowitz+Stegun, 23.2.5] */ + + gsl_sf_result zeta_one_minus_s; + const int stat_zoms = riemann_zeta1ms_slt0(s, &zeta_one_minus_s); + const double sin_term = (fmod(s,2.0) == 0.0) ? 0.0 : sin(0.5*M_PI*fmod(s,4.0))/M_PI; + + if(sin_term == 0.0) { + result->val = 0.0; + result->err = 0.0; + return GSL_SUCCESS; + } + else if(s > -170) { + /* We have to be careful about losing digits + * in calculating pow(2 Pi, s). The gamma + * function is fine because we were careful + * with that implementation. + * We keep an array of (2 Pi)^(10 n). + */ + const double twopi_pow[18] = { 1.0, + 9.589560061550901348e+007, + 9.195966217409212684e+015, + 8.818527036583869903e+023, + 8.456579467173150313e+031, + 8.109487671573504384e+039, + 7.776641909496069036e+047, + 7.457457466828644277e+055, + 7.151373628461452286e+063, + 6.857852693272229709e+071, + 6.576379029540265771e+079, + 6.306458169130020789e+087, + 6.047615938853066678e+095, + 5.799397627482402614e+103, + 5.561367186955830005e+111, + 5.333106466365131227e+119, + 5.114214477385391780e+127, + 4.904306689854036836e+135 + }; + const int n = floor((-s)/10.0); + const double fs = s + 10.0*n; + const double p = pow(2.0*M_PI, fs) / twopi_pow[n]; + + gsl_sf_result g; + const int stat_g = gsl_sf_gamma_e(1.0-s, &g); + result->val = p * g.val * sin_term * zeta_one_minus_s.val; + result->err = fabs(p * g.val * sin_term) * zeta_one_minus_s.err; + result->err += fabs(p * sin_term * zeta_one_minus_s.val) * g.err; + result->err += GSL_DBL_EPSILON * (fabs(s)+2.0) * fabs(result->val); + return GSL_ERROR_SELECT_2(stat_g, stat_zoms); + } + else { + /* The actual zeta function may or may not + * overflow here. But we have no easy way + * to calculate it when the prefactor(s) + * overflow. Trying to use log's and exp + * is no good because we loose a couple + * digits to the exp error amplification. + * When we gather a little more patience, + * we can implement something here. Until + * then just give up. + */ + OVERFLOW_ERROR(result); + } + } +} + + +int gsl_sf_zeta_int_e(const int n, gsl_sf_result * result) +{ + /* CHECK_POINTER(result) */ + + if(n < 0) { + if(!GSL_IS_ODD(n)) { + result->val = 0.0; /* exactly zero at even negative integers */ + result->err = 0.0; + return GSL_SUCCESS; + } + else if(n > -ZETA_NEG_TABLE_NMAX) { + result->val = zeta_neg_int_table[-(n+1)/2]; + result->err = 2.0 * GSL_DBL_EPSILON * fabs(result->val); + return GSL_SUCCESS; + } + else { + return gsl_sf_zeta_e((double)n, result); + } + } + else if(n == 1){ + DOMAIN_ERROR(result); + } + else if(n <= ZETA_POS_TABLE_NMAX){ + result->val = 1.0 + zetam1_pos_int_table[n]; + result->err = 2.0 * GSL_DBL_EPSILON * fabs(result->val); + return GSL_SUCCESS; + } + else { + result->val = 1.0; + result->err = GSL_DBL_EPSILON; + return GSL_SUCCESS; + } +} + + +int gsl_sf_zetam1_e(const double s, gsl_sf_result * result) +{ + if(s <= 5.0) + { + int stat = gsl_sf_zeta_e(s, result); + result->val = result->val - 1.0; + return stat; + } + else if(s < 15.0) + { + return riemann_zeta_minus_1_intermediate_s(s, result); + } + else + { + return riemann_zeta_minus1_large_s(s, result); + } +} + + +int gsl_sf_zetam1_int_e(const int n, gsl_sf_result * result) +{ + if(n < 0) { + if(!GSL_IS_ODD(n)) { + result->val = -1.0; /* at even negative integers zetam1 == -1 since zeta is exactly zero */ + result->err = 0.0; + return GSL_SUCCESS; + } + else if(n > -ZETA_NEG_TABLE_NMAX) { + result->val = zeta_neg_int_table[-(n+1)/2] - 1.0; + result->err = 2.0 * GSL_DBL_EPSILON * fabs(result->val); + return GSL_SUCCESS; + } + else { + /* could use gsl_sf_zetam1_e here but subtracting 1 makes no difference + for such large values, so go straight to the result */ + return gsl_sf_zeta_e((double)n, result); + } + } + else if(n == 1){ + DOMAIN_ERROR(result); + } + else if(n <= ZETA_POS_TABLE_NMAX){ + result->val = zetam1_pos_int_table[n]; + result->err = 2.0 * GSL_DBL_EPSILON * fabs(result->val); + return GSL_SUCCESS; + } + else { + return gsl_sf_zetam1_e(n, result); + } +} + + +int gsl_sf_eta_int_e(int n, gsl_sf_result * result) +{ + if(n > ETA_POS_TABLE_NMAX) { + result->val = 1.0; + result->err = GSL_DBL_EPSILON; + return GSL_SUCCESS; + } + else if(n >= 0) { + result->val = eta_pos_int_table[n]; + result->err = 2.0 * GSL_DBL_EPSILON * fabs(result->val); + return GSL_SUCCESS; + } + else { + /* n < 0 */ + + if(!GSL_IS_ODD(n)) { + /* exactly zero at even negative integers */ + result->val = 0.0; + result->err = 0.0; + return GSL_SUCCESS; + } + else if(n > -ETA_NEG_TABLE_NMAX) { + result->val = eta_neg_int_table[-(n+1)/2]; + result->err = 2.0 * GSL_DBL_EPSILON * fabs(result->val); + return GSL_SUCCESS; + } + else { + gsl_sf_result z; + gsl_sf_result p; + int stat_z = gsl_sf_zeta_int_e(n, &z); + int stat_p = gsl_sf_exp_e((1.0-n)*M_LN2, &p); + int stat_m = gsl_sf_multiply_e(-p.val, z.val, result); + result->err = fabs(p.err * (M_LN2*(1.0-n)) * z.val) + z.err * fabs(p.val); + result->err += 2.0 * GSL_DBL_EPSILON * fabs(result->val); + return GSL_ERROR_SELECT_3(stat_m, stat_p, stat_z); + } + } +} + + +int gsl_sf_eta_e(const double s, gsl_sf_result * result) +{ + /* CHECK_POINTER(result) */ + + if(s > 100.0) { + result->val = 1.0; + result->err = GSL_DBL_EPSILON; + return GSL_SUCCESS; + } + else if(fabs(s-1.0) < 10.0*GSL_ROOT5_DBL_EPSILON) { + double del = s-1.0; + double c0 = M_LN2; + double c1 = M_LN2 * (M_EULER - 0.5*M_LN2); + double c2 = -0.0326862962794492996; + double c3 = 0.0015689917054155150; + double c4 = 0.00074987242112047532; + result->val = c0 + del * (c1 + del * (c2 + del * (c3 + del * c4))); + result->err = 2.0 * GSL_DBL_EPSILON * fabs(result->val); + return GSL_SUCCESS; + } + else { + gsl_sf_result z; + gsl_sf_result p; + int stat_z = gsl_sf_zeta_e(s, &z); + int stat_p = gsl_sf_exp_e((1.0-s)*M_LN2, &p); + int stat_m = gsl_sf_multiply_e(1.0-p.val, z.val, result); + result->err = fabs(p.err * (M_LN2*(1.0-s)) * z.val) + z.err * fabs(p.val); + result->err += 2.0 * GSL_DBL_EPSILON * fabs(result->val); + return GSL_ERROR_SELECT_3(stat_m, stat_p, stat_z); + } +} + + +/*-*-*-*-*-*-*-*-*-* Functions w/ Natural Prototypes *-*-*-*-*-*-*-*-*-*-*/ + +#include "eval.h" + +double gsl_sf_zeta(const double s) +{ + EVAL_RESULT(gsl_sf_zeta_e(s, &result)); +} + +double gsl_sf_hzeta(const double s, const double a) +{ + EVAL_RESULT(gsl_sf_hzeta_e(s, a, &result)); +} + +double gsl_sf_zeta_int(const int s) +{ + EVAL_RESULT(gsl_sf_zeta_int_e(s, &result)); +} + +double gsl_sf_zetam1(const double s) +{ + EVAL_RESULT(gsl_sf_zetam1_e(s, &result)); +} + +double gsl_sf_zetam1_int(const int s) +{ + EVAL_RESULT(gsl_sf_zetam1_int_e(s, &result)); +} + +double gsl_sf_eta_int(const int s) +{ + EVAL_RESULT(gsl_sf_eta_int_e(s, &result)); +} + +double gsl_sf_eta(const double s) +{ + EVAL_RESULT(gsl_sf_eta_e(s, &result)); +} |