/src/gstreamer/subprojects/gst-plugins-base/gst-libs/gst/audio/dbesi0.c
Line | Count | Source |
1 | | /* Copyright(C) 1996 Takuya OOURA |
2 | | |
3 | | You may use, copy, modify this code for any purpose and |
4 | | without fee. |
5 | | |
6 | | Package home: http://www.kurims.kyoto-u.ac.jp/~ooura/bessel.html |
7 | | */ |
8 | | |
9 | | /* Bessel I_0(x) function in double precision */ |
10 | | |
11 | | #include <math.h> |
12 | | |
13 | | static double |
14 | | dbesi0 (double x) |
15 | 0 | { |
16 | 0 | int k; |
17 | 0 | double w, t, y; |
18 | 0 | static double a[65] = { |
19 | 0 | 8.5246820682016865877e-11, 2.5966600546497407288e-9, |
20 | 0 | 7.9689994568640180274e-8, 1.9906710409667748239e-6, |
21 | 0 | 4.0312469446528002532e-5, 6.4499871606224265421e-4, |
22 | 0 | 0.0079012345761930579108, 0.071111111109207045212, |
23 | 0 | 0.444444444444724909, 1.7777777777777532045, |
24 | 0 | 4.0000000000000011182, 3.99999999999999998, |
25 | 0 | 1.0000000000000000001, |
26 | 0 | 1.1520919130377195927e-10, 2.2287613013610985225e-9, |
27 | 0 | 8.1903951930694585113e-8, 1.9821560631611544984e-6, |
28 | 0 | 4.0335461940910133184e-5, 6.4495330974432203401e-4, |
29 | 0 | 0.0079013012611467520626, 0.071111038160875566622, |
30 | 0 | 0.44444450319062699316, 1.7777777439146450067, |
31 | 0 | 4.0000000132337935071, 3.9999999968569015366, |
32 | 0 | 1.0000000003426703174, |
33 | 0 | 1.5476870780515238488e-10, 1.2685004214732975355e-9, |
34 | 0 | 9.2776861851114223267e-8, 1.9063070109379044378e-6, |
35 | 0 | 4.0698004389917945832e-5, 6.4370447244298070713e-4, |
36 | 0 | 0.0079044749458444976958, 0.071105052411749363882, |
37 | 0 | 0.44445280640924755082, 1.7777694934432109713, |
38 | 0 | 4.0000055808824003386, 3.9999977081165740932, |
39 | 0 | 1.0000004333949319118, |
40 | 0 | 2.0675200625006793075e-10, -6.1689554705125681442e-10, |
41 | 0 | 1.2436765915401571654e-7, 1.5830429403520613423e-6, |
42 | 0 | 4.2947227560776583326e-5, 6.3249861665073441312e-4, |
43 | 0 | 0.0079454472840953930811, 0.070994327785661860575, |
44 | 0 | 0.44467219586283000332, 1.7774588182255374745, |
45 | 0 | 4.0003038986252717972, 3.9998233869142057195, |
46 | 0 | 1.0000472932961288324, |
47 | 0 | 2.7475684794982708655e-10, -3.8991472076521332023e-9, |
48 | 0 | 1.9730170483976049388e-7, 5.9651531561967674521e-7, |
49 | 0 | 5.1992971474748995357e-5, 5.7327338675433770752e-4, |
50 | 0 | 0.0082293143836530412024, 0.069990934858728039037, |
51 | 0 | 0.44726764292723985087, 1.7726685170014087784, |
52 | 0 | 4.0062907863712704432, 3.9952750700487845355, |
53 | 0 | 1.0016354346654179322 |
54 | 0 | }; |
55 | 0 | static double b[70] = { |
56 | 0 | 6.7852367144945531383e-8, 4.6266061382821826854e-7, |
57 | 0 | 6.9703135812354071774e-6, 7.6637663462953234134e-5, |
58 | 0 | 7.9113515222612691636e-4, 0.0073401204731103808981, |
59 | 0 | 0.060677114958668837046, 0.43994941411651569622, |
60 | 0 | 2.7420017097661750609, 14.289661921740860534, |
61 | 0 | 59.820609640320710779, 188.78998681199150629, |
62 | 0 | 399.8731367825601118, 427.56411572180478514, |
63 | 0 | 1.8042097874891098754e-7, 1.2277164312044637357e-6, |
64 | 0 | 1.8484393221474274861e-5, 2.0293995900091309208e-4, |
65 | 0 | 0.0020918539850246207459, 0.019375315654033949297, |
66 | 0 | 0.15985869016767185908, 1.1565260527420641724, |
67 | 0 | 7.1896341224206072113, 37.354773811947484532, |
68 | 0 | 155.80993164266268457, 489.5211371158540918, |
69 | 0 | 1030.9147225169564806, 1093.5883545113746958, |
70 | 0 | 4.8017305613187493564e-7, 3.261317843912380074e-6, |
71 | 0 | 4.9073137508166159639e-5, 5.3806506676487583755e-4, |
72 | 0 | 0.0055387918291051866561, 0.051223717488786549025, |
73 | 0 | 0.42190298621367914765, 3.0463625987357355872, |
74 | 0 | 18.895299447327733204, 97.915189029455461554, |
75 | 0 | 407.13940115493494659, 1274.3088990480582632, |
76 | 0 | 2670.9883037012547506, 2815.7166284662544712, |
77 | 0 | 1.2789926338424623394e-6, 8.6718263067604918916e-6, |
78 | 0 | 1.3041508821299929489e-4, 0.001428224737372747892, |
79 | 0 | 0.014684070635768789378, 0.13561403190404185755, |
80 | 0 | 1.1152592585977393953, 8.0387088559465389038, |
81 | 0 | 49.761318895895479206, 257.2684232313529138, |
82 | 0 | 1066.8543146269566231, 3328.3874581009636362, |
83 | 0 | 6948.8586598121634874, 7288.4893398212481055, |
84 | 0 | 3.409350368197032893e-6, 2.3079025203103376076e-5, |
85 | 0 | 3.4691373283901830239e-4, 0.003794994977222908545, |
86 | 0 | 0.038974209677945602145, 0.3594948380414878371, |
87 | 0 | 2.9522878893539528226, 21.246564609514287056, |
88 | 0 | 131.28727387146173141, 677.38107093296675421, |
89 | 0 | 2802.3724744545046518, 8718.5731420798254081, |
90 | 0 | 18141.348781638832286, 18948.925349296308859 |
91 | 0 | }; |
92 | 0 | static double c[45] = { |
93 | 0 | 2.5568678676452702768e-15, 3.0393953792305924324e-14, |
94 | 0 | 6.3343751991094840009e-13, 1.5041298011833009649e-11, |
95 | 0 | 4.4569436918556541414e-10, 1.746393051427167951e-8, |
96 | 0 | 1.0059224011079852317e-6, 1.0729838945088577089e-4, |
97 | 0 | 0.05150322693642527738, |
98 | 0 | 5.2527963991711562216e-15, 7.202118481421005641e-15, |
99 | 0 | 7.2561421229904797156e-13, 1.482312146673104251e-11, |
100 | 0 | 4.4602670450376245434e-10, 1.7463600061788679671e-8, |
101 | 0 | 1.005922609132234756e-6, 1.0729838937545111487e-4, |
102 | 0 | 0.051503226936437300716, |
103 | 0 | 1.3365917359358069908e-14, -1.2932643065888544835e-13, |
104 | 0 | 1.7450199447905602915e-12, 1.0419051209056979788e-11, |
105 | 0 | 4.58047881980598326e-10, 1.7442405450073548966e-8, |
106 | 0 | 1.0059461453281292278e-6, 1.0729837434500161228e-4, |
107 | 0 | 0.051503226940658446941, |
108 | 0 | 5.3771611477352308649e-14, -1.1396193006413731702e-12, |
109 | 0 | 1.2858641335221653409e-11, -5.9802086004570057703e-11, |
110 | 0 | 7.3666894305929510222e-10, 1.6731837150730356448e-8, |
111 | 0 | 1.0070831435812128922e-6, 1.0729733111203704813e-4, |
112 | 0 | 0.051503227360726294675, |
113 | 0 | 3.7819492084858931093e-14, -4.8600496888588034879e-13, |
114 | 0 | 1.6898350504817224909e-12, 4.5884624327524255865e-11, |
115 | 0 | 1.2521615963377513729e-10, 1.8959658437754727957e-8, |
116 | 0 | 1.0020716710561353622e-6, 1.073037119856927559e-4, |
117 | 0 | 0.05150322383300230775 |
118 | 0 | }; |
119 | |
|
120 | 0 | w = fabs (x); |
121 | 0 | if (w < 8.5) { |
122 | 0 | t = w * w * 0.0625; |
123 | 0 | k = 13 * ((int) t); |
124 | 0 | y = (((((((((((a[k] * t + a[k + 1]) * t + |
125 | 0 | a[k + 2]) * t + a[k + 3]) * t + |
126 | 0 | a[k + 4]) * t + a[k + 5]) * t + a[k + |
127 | 0 | 6]) * t + a[k + 7]) * t + a[k + 8]) * t + a[k + |
128 | 0 | 9]) * t + a[k + 10]) * t + a[k + 11]) * t + a[k + 12]; |
129 | 0 | } else if (w < 12.5) { |
130 | 0 | k = (int) w; |
131 | 0 | t = w - k; |
132 | 0 | k = 14 * (k - 8); |
133 | 0 | y = ((((((((((((b[k] * t + b[k + 1]) * t + b[k + 2]) * t + b[k + 3]) * t + |
134 | 0 | b[k + 4]) * t + b[k + 5]) * t + b[k + |
135 | 0 | 6]) * t + b[k + 7]) * t + b[k + 8]) * t + |
136 | 0 | b[k + 9]) * t + b[k + 10]) * t + b[k + 11]) * t + b[k + |
137 | 0 | 12]) * t + b[k + 13]; |
138 | 0 | } else { |
139 | 0 | t = 60 / w; |
140 | 0 | k = 9 * ((int) t); |
141 | 0 | y = ((((((((c[k] * t + c[k + 1]) * t + |
142 | 0 | c[k + 2]) * t + c[k + 3]) * t + c[k + 4]) * t + |
143 | 0 | c[k + 5]) * t + c[k + 6]) * t + c[k + 7]) * t + |
144 | 0 | c[k + 8]) * sqrt (t) * exp (w); |
145 | 0 | } |
146 | 0 | return y; |
147 | 0 | } |