1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
|
/* Copyright (C) 2017 - IIT Bombay - FOSSEE
This file must be used under the terms of the CeCILL.
This source file is licensed as described in the file COPYING, which
you should have received as part of this distribution. The terms
are also available at
http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt
Organization: FOSSEE, IIT Bombay
Author: Brijesh Gupta C R
Email: toolbox@scilab.in
*/
#include <stdio.h>
#include "math.h"
#include "besselj.h"
#define ACC 40.0
#define BIGNO 1.0e10
#define BIGNI 1.0e-10
static float fbessj0( float x )
{
float ax,z;
float xx,y,ans,ans1,ans2;
if ((ax=fabs(x)) < 8.0) {
y=x*x;
ans1=57568490574.0+y*(-13362590354.0+y*(651619640.7
+y*(-11214424.18+y*(77392.33017+y*(-184.9052456)))));
ans2=57568490411.0+y*(1029532985.0+y*(9494680.718
+y*(59272.64853+y*(267.8532712+y*1.0))));
ans=ans1/ans2;
} else {
z=8.0/ax;
y=z*z;
xx=ax-0.785398164;
ans1=1.0+y*(-0.1098628627e-2+y*(0.2734510407e-4
+y*(-0.2073370639e-5+y*0.2093887211e-6)));
ans2 = -0.1562499995e-1+y*(0.1430488765e-3
+y*(-0.6911147651e-5+y*(0.7621095161e-6
-y*0.934935152e-7)));
ans=sqrt(0.636619772/ax)*(cos(xx)*ans1-z*sin(xx)*ans2);
}
return ans;
}
static float fbessj1( float x )
{
float ax,z;
float xx,y,ans,ans1,ans2;
if ((ax=fabs(x)) < 8.0) {
y=x*x;
ans1=x*(72362614232.0+y*(-7895059235.0+y*(242396853.1
+y*(-2972611.439+y*(15704.48260+y*(-30.16036606))))));
ans2=144725228442.0+y*(2300535178.0+y*(18583304.74
+y*(99447.43394+y*(376.9991397+y*1.0))));
ans=ans1/ans2;
} else {
z=8.0/ax;
y=z*z;
xx=ax-2.356194491;
ans1=1.0+y*(0.183105e-2+y*(-0.3516396496e-4
+y*(0.2457520174e-5+y*(-0.240337019e-6))));
ans2=0.04687499995+y*(-0.2002690873e-3
+y*(0.8449199096e-5+y*(-0.88228987e-6
+y*0.105787412e-6)));
ans=sqrt(0.636619772/ax)*(cos(xx)*ans1-z*sin(xx)*ans2);
if (x < 0.0) ans = -ans;
}
return ans;
}
float fbessj( int n, float x )
{
int j, jsum, m;
float ax, bj, bjm, bjp, sum, tox, ans;
if (n < 0)
{
float dblank;
return( dblank );
}
ax=fabs(x);
if (n == 0)
return( fbessj0(ax) );
if (n == 1)
return( fbessj1(ax) );
if (ax == 0.0)
return 0.0;
else if (ax > (float) n) {
tox=2.0/ax;
bjm=fbessj0(ax);
bj=fbessj1(ax);
for (j=1;j<n;j++) {
bjp=j*tox*bj-bjm;
bjm=bj;
bj=bjp;
}
ans=bj;
} else {
tox=2.0/ax;
m=2*((n+(int) sqrt(ACC*n))/2);
jsum=0;
bjp=ans=sum=0.0;
bj=1.0;
for (j=m;j>0;j--) {
bjm=j*tox*bj-bjp;
bjp=bj;
bj=bjm;
if (fabs(bj) > BIGNO) {
bj *= BIGNI;
bjp *= BIGNI;
ans *= BIGNI;
sum *= BIGNI;
}
if (jsum) sum += bj;
jsum=!jsum;
if (j == n) ans=bjp;
}
sum=2.0*sum-bj;
ans /= sum;
}
return x < 0.0 && n%2 == 1 ? -ans : ans;
}
void sbesselja(float* inp1,int size1, float* inp2,int size2, float* oup)
{
int i;
if(size1 != size2)
printf("Error! arguments #1 and #2 have incompatible dimensions.");
for(i = 0; i<size1;i++)
{
oup[i] = fbessj(inp1[i],inp2[i]);
}
}
|
