besj0.f
4.88 KB
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
function besj0 (x)
c april 1977 version. w. fullerton, c3, los alamos scientific lab.
dimension bj0cs(13), bm0cs(21), bth0cs(24)
external csevl, inits, r1mach
c
c series for bj0 on the interval 0. to 1.60000d+01
c with weighted error 7.47e-18
c log weighted error 17.13
c significant figures required 16.98
c decimal places required 17.68
c
data bj0 cs( 1) / .1002541619 68939137e0 /
data bj0 cs( 2) / -.6652230077 64405132e0 /
data bj0 cs( 3) / .2489837034 98281314e0 /
data bj0 cs( 4) / -.0332527231 700357697e0 /
data bj0 cs( 5) / .0023114179 304694015e0 /
data bj0 cs( 6) / -.0000991127 741995080e0 /
data bj0 cs( 7) / .0000028916 708643998e0 /
data bj0 cs( 8) / -.0000000612 108586630e0 /
data bj0 cs( 9) / .0000000009 838650793e0 /
data bj0 cs(10) / -.0000000000 124235515e0 /
data bj0 cs(11) / .0000000000 001265433e0 /
data bj0 cs(12) / -.0000000000 000010619e0 /
data bj0 cs(13) / .0000000000 000000074e0 /
c
c series for bm0 on the interval 0. to 6.25000d-02
c with weighted error 4.98e-17
c log weighted error 16.30
c significant figures required 14.97
c decimal places required 16.96
c
data bm0 cs( 1) / .0928496163 7381644e0 /
data bm0 cs( 2) / -.0014298770 7403484e0 /
data bm0 cs( 3) / .0000283057 9271257e0 /
data bm0 cs( 4) / -.0000014330 0611424e0 /
data bm0 cs( 5) / .0000001202 8628046e0 /
data bm0 cs( 6) / -.0000000139 7113013e0 /
data bm0 cs( 7) / .0000000020 4076188e0 /
data bm0 cs( 8) / -.0000000003 5399669e0 /
data bm0 cs( 9) / .0000000000 7024759e0 /
data bm0 cs(10) / -.0000000000 1554107e0 /
data bm0 cs(11) / .0000000000 0376226e0 /
data bm0 cs(12) / -.0000000000 0098282e0 /
data bm0 cs(13) / .0000000000 0027408e0 /
data bm0 cs(14) / -.0000000000 0008091e0 /
data bm0 cs(15) / .0000000000 0002511e0 /
data bm0 cs(16) / -.0000000000 0000814e0 /
data bm0 cs(17) / .0000000000 0000275e0 /
data bm0 cs(18) / -.0000000000 0000096e0 /
data bm0 cs(19) / .0000000000 0000034e0 /
data bm0 cs(20) / -.0000000000 0000012e0 /
data bm0 cs(21) / .0000000000 0000004e0 /
c
c series for bth0 on the interval 0. to 6.25000d-02
c with weighted error 3.67e-17
c log weighted error 16.44
c significant figures required 15.53
c decimal places required 17.13
c
data bth0cs( 1) / -.2463916377 4300119e0 /
data bth0cs( 2) / .0017370983 07508963e0 /
data bth0cs( 3) / -.0000621836 33402968e0 /
data bth0cs( 4) / .0000043680 50165742e0 /
data bth0cs( 5) / -.0000004560 93019869e0 /
data bth0cs( 6) / .0000000621 97400101e0 /
data bth0cs( 7) / -.0000000103 00442889e0 /
data bth0cs( 8) / .0000000019 79526776e0 /
data bth0cs( 9) / -.0000000004 28198396e0 /
data bth0cs(10) / .0000000001 02035840e0 /
data bth0cs(11) / -.0000000000 26363898e0 /
data bth0cs(12) / .0000000000 07297935e0 /
data bth0cs(13) / -.0000000000 02144188e0 /
data bth0cs(14) / .0000000000 00663693e0 /
data bth0cs(15) / -.0000000000 00215126e0 /
data bth0cs(16) / .0000000000 00072659e0 /
data bth0cs(17) / -.0000000000 00025465e0 /
data bth0cs(18) / .0000000000 00009229e0 /
data bth0cs(19) / -.0000000000 00003448e0 /
data bth0cs(20) / .0000000000 00001325e0 /
data bth0cs(21) / -.0000000000 00000522e0 /
data bth0cs(22) / .0000000000 00000210e0 /
data bth0cs(23) / -.0000000000 00000087e0 /
data bth0cs(24) / .0000000000 00000036e0 /
c
data pi4 / 0.7853981633 9744831e0 /
data ntj0, ntm0, ntth0, xsml, xmax / 3*0, 2*0./
c
if (ntj0.ne.0) go to 10
ntj0 = inits (bj0cs, 13, 0.1*r1mach(3))
ntm0 = inits (bm0cs, 21, 0.1*r1mach(3))
ntth0 = inits (bth0cs, 24, 0.1*r1mach(3))
c
xsml = sqrt (4.0*r1mach(3))
xmax = 1.0/r1mach(4)
c
10 y = abs(x)
if (y.gt.4.0) go to 20
c
besj0 = 1.0
if (y.gt.xsml) besj0 = csevl (.125*y*y-1., bj0cs, ntj0)
return
c
20 if (y.gt.xmax) call seteru (
1 42hbesj0 no precision because abs(x) is big, 42, 1, 2)
c
z = 32.0/y**2 - 1.0
ampl = (0.75 + csevl (z, bm0cs, ntm0)) / sqrt(y)
theta = y - pi4 + csevl (z, bth0cs, ntth0) / y
besj0 = ampl * cos (theta)
c
return
end