3 * Copyright (C) 1996, 1997, 1998, 1999, 2000 Gerard Jungman
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 3 of the License, or (at
8 * your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20 /* Author: G. Jungman */
23 #include <gsl/gsl_math.h>
24 #include <gsl/gsl_errno.h>
25 #include <gsl/gsl_sf_dawson.h>
28 #include "chebyshev.h"
29 #include "cheb_eval.c"
31 /* Based on ddaws.f, Fullerton, W., (LANL) */
34 /* Chebyshev expansions
36 Series for DAW on the interval 0. to 1.00000E+00
37 with weighted error 8.95E-32
38 log weighted error 31.05
39 significant figures required 30.41
40 decimal places required 31.71
42 Series for DAW2 on the interval 0. to 1.60000E+01
43 with weighted error 1.61E-32
44 log weighted error 31.79
45 significant figures required 31.40
46 decimal places required 32.62
48 Series for DAWA on the interval 0. to 6.25000E-02
49 with weighted error 1.97E-32
50 log weighted error 31.71
51 significant figures required 29.79
52 decimal places required 32.64
54 static double daw_data[21] = {
55 -0.6351734375145949201065127736293e-02,
56 -0.2294071479677386939899824125866e+00,
57 0.2213050093908476441683979161786e-01,
58 -0.1549265453892985046743057753375e-02,
59 0.8497327715684917456777542948066e-04,
60 -0.3828266270972014924994099521309e-05,
61 0.1462854806250163197757148949539e-06,
62 -0.4851982381825991798846715425114e-08,
63 0.1421463577759139790347568183304e-09,
64 -0.3728836087920596525335493054088e-11,
65 0.8854942961778203370194565231369e-13,
66 -0.1920757131350206355421648417493e-14,
67 0.3834325867246327588241074439253e-16,
68 -0.7089154168175881633584099327999e-18,
69 0.1220552135889457674416901120000e-19,
70 -0.1966204826605348760299451733333e-21,
71 0.2975845541376597189113173333333e-23,
72 -0.4247069514800596951039999999999e-25,
73 0.5734270767391742798506666666666e-27,
74 -0.7345836823178450261333333333333e-29,
75 0.8951937667516552533333333333333e-31
77 static cheb_series daw_cs = {
84 static double daw2_data[45] = {
85 -0.56886544105215527114160533733674e-01,
86 -0.31811346996168131279322878048822e+00,
87 0.20873845413642236789741580198858e+00,
88 -0.12475409913779131214073498314784e+00,
89 0.67869305186676777092847516423676e-01,
90 -0.33659144895270939503068230966587e-01,
91 0.15260781271987971743682460381640e-01,
92 -0.63483709625962148230586094788535e-02,
93 0.24326740920748520596865966109343e-02,
94 -0.86219541491065032038526983549637e-03,
95 0.28376573336321625302857636538295e-03,
96 -0.87057549874170423699396581464335e-04,
97 0.24986849985481658331800044137276e-04,
98 -0.67319286764160294344603050339520e-05,
99 0.17078578785573543710504524047844e-05,
100 -0.40917551226475381271896592490038e-06,
101 0.92828292216755773260751785312273e-07,
102 -0.19991403610147617829845096332198e-07,
103 0.40963490644082195241210487868917e-08,
104 -0.80032409540993168075706781753561e-09,
105 0.14938503128761465059143225550110e-09,
106 -0.26687999885622329284924651063339e-10,
107 0.45712216985159458151405617724103e-11,
108 -0.75187305222043565872243727326771e-12,
109 0.11893100052629681879029828987302e-12,
110 -0.18116907933852346973490318263084e-13,
111 0.26611733684358969193001612199626e-14,
112 -0.37738863052129419795444109905930e-15,
113 0.51727953789087172679680082229329e-16,
114 -0.68603684084077500979419564670102e-17,
115 0.88123751354161071806469337321745e-18,
116 -0.10974248249996606292106299624652e-18,
117 0.13261199326367178513595545891635e-19,
118 -0.15562732768137380785488776571562e-20,
119 0.17751425583655720607833415570773e-21,
120 -0.19695006967006578384953608765439e-22,
121 0.21270074896998699661924010120533e-23,
122 -0.22375398124627973794182113962666e-24,
123 0.22942768578582348946971383125333e-25,
124 -0.22943788846552928693329592319999e-26,
125 0.22391702100592453618342297600000e-27,
126 -0.21338230616608897703678225066666e-28,
127 0.19866196585123531518028458666666e-29,
128 -0.18079295866694391771955199999999e-30,
129 0.16090686015283030305450666666666e-31
131 static cheb_series daw2_cs = {
138 static double dawa_data[75] = {
139 0.1690485637765703755422637438849e-01,
140 0.8683252278406957990536107850768e-02,
141 0.2424864042417715453277703459889e-03,
142 0.1261182399572690001651949240377e-04,
143 0.1066453314636176955705691125906e-05,
144 0.1358159794790727611348424505728e-06,
145 0.2171042356577298398904312744743e-07,
146 0.2867010501805295270343676804813e-08,
147 -0.1901336393035820112282492378024e-09,
148 -0.3097780484395201125532065774268e-09,
149 -0.1029414876057509247398132286413e-09,
150 -0.6260356459459576150417587283121e-11,
151 0.8563132497446451216262303166276e-11,
152 0.3033045148075659292976266276257e-11,
153 -0.2523618306809291372630886938826e-12,
154 -0.4210604795440664513175461934510e-12,
155 -0.4431140826646238312143429452036e-13,
156 0.4911210272841205205940037065117e-13,
157 0.1235856242283903407076477954739e-13,
158 -0.5788733199016569246955765071069e-14,
159 -0.2282723294807358620978183957030e-14,
160 0.7637149411014126476312362917590e-15,
161 0.3851546883566811728777594002095e-15,
162 -0.1199932056928290592803237283045e-15,
163 -0.6313439150094572347334270285250e-16,
164 0.2239559965972975375254912790237e-16,
165 0.9987925830076495995132891200749e-17,
166 -0.4681068274322495334536246507252e-17,
167 -0.1436303644349721337241628751534e-17,
168 0.1020822731410541112977908032130e-17,
169 0.1538908873136092072837389822372e-18,
170 -0.2189157877645793888894790926056e-18,
171 0.2156879197938651750392359152517e-20,
172 0.4370219827442449851134792557395e-19,
173 -0.8234581460977207241098927905177e-20,
174 -0.7498648721256466222903202835420e-20,
175 0.3282536720735671610957612930039e-20,
176 0.8858064309503921116076561515151e-21,
177 -0.9185087111727002988094460531485e-21,
178 0.2978962223788748988314166045791e-22,
179 0.1972132136618471883159505468041e-21,
180 -0.5974775596362906638089584995117e-22,
181 -0.2834410031503850965443825182441e-22,
182 0.2209560791131554514777150489012e-22,
183 -0.5439955741897144300079480307711e-25,
184 -0.5213549243294848668017136696470e-23,
185 0.1702350556813114199065671499076e-23,
186 0.6917400860836148343022185660197e-24,
187 -0.6540941793002752512239445125802e-24,
188 0.6093576580439328960371824654636e-25,
189 0.1408070432905187461501945080272e-24,
190 -0.6785886121054846331167674943755e-25,
191 -0.9799732036214295711741583102225e-26,
192 0.2121244903099041332598960939160e-25,
193 -0.5954455022548790938238802154487e-26,
194 -0.3093088861875470177838847232049e-26,
195 0.2854389216344524682400691986104e-26,
196 -0.3951289447379305566023477271811e-27,
197 -0.5906000648607628478116840894453e-27,
198 0.3670236964668687003647889980609e-27,
199 -0.4839958238042276256598303038941e-29,
200 -0.9799265984210443869597404017022e-28,
201 0.4684773732612130606158908804300e-28,
202 0.5030877696993461051647667603155e-29,
203 -0.1547395051706028239247552068295e-28,
204 0.6112180185086419243976005662714e-29,
205 0.1357913399124811650343602736158e-29,
206 -0.2417687752768673088385304299044e-29,
207 0.8369074582074298945292887587291e-30,
208 0.2665413042788979165838319401566e-30,
209 -0.3811653692354890336935691003712e-30,
210 0.1230054721884951464371706872585e-30,
211 0.4622506399041493508805536929983e-31,
212 -0.6120087296881677722911435593001e-31,
213 0.1966024640193164686956230217896e-31
215 static cheb_series dawa_cs = {
223 /*-*-*-*-*-*-*-*-*-*-*-* Functions with Error Codes *-*-*-*-*-*-*-*-*-*-*-*/
226 gsl_sf_dawson_e(double x, gsl_sf_result * result)
228 const double xsml = 1.225 * GSL_SQRT_DBL_EPSILON;
229 const double xbig = 1.0/(M_SQRT2*GSL_SQRT_DBL_EPSILON);
230 const double xmax = 0.1 * GSL_DBL_MAX;
232 const double y = fabs(x);
240 gsl_sf_result result_c;
241 cheb_eval_e(&daw_cs, 2.0*y*y - 1.0, &result_c);
242 result->val = x * (0.75 + result_c.val);
243 result->err = y * result_c.err;
244 result->err += 2.0 * GSL_DBL_EPSILON * fabs(result->val);
248 gsl_sf_result result_c;
249 cheb_eval_e(&daw2_cs, 0.125*y*y - 1.0, &result_c);
250 result->val = x * (0.25 + result_c.val);
251 result->err = y * result_c.err;
252 result->err += 2.0 * GSL_DBL_EPSILON * fabs(result->val);
256 gsl_sf_result result_c;
257 cheb_eval_e(&dawa_cs, 32.0/(y*y) - 1.0, &result_c);
258 result->val = (0.5 + result_c.val) / x;
259 result->err = result_c.err / y;
260 result->err += 2.0 * GSL_DBL_EPSILON * fabs(result->val);
265 result->err = 2.0 * GSL_DBL_EPSILON * result->val;
269 UNDERFLOW_ERROR(result);
274 /*-*-*-*-*-*-*-*-*-* Functions w/ Natural Prototypes *-*-*-*-*-*-*-*-*-*-*/
278 double gsl_sf_dawson(double x)
280 EVAL_RESULT(gsl_sf_dawson_e(x, &result));