1j0(3) Library Functions Manual j0(3)
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6 j0, j0f, j0l, j1, j1f, j1l, jn, jnf, jnl - Bessel functions of the
7 first kind
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10 Math library (libm, -lm)
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13 #include <math.h>
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15 double j0(double x);
16 double j1(double x);
17 double jn(int n, double x);
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19 float j0f(float x);
20 float j1f(float x);
21 float jnf(int n, float x);
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23 long double j0l(long double x);
24 long double j1l(long double x);
25 long double jnl(int n, long double x);
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27 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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29 j0(), j1(), jn():
30 _XOPEN_SOURCE
31 || /* Since glibc 2.19: */ _DEFAULT_SOURCE
32 || /* glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
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34 j0f(), j0l(), j1f(), j1l(), jnf(), jnl():
35 _XOPEN_SOURCE >= 600
36 || (_ISOC99_SOURCE && _XOPEN_SOURCE)
37 || /* Since glibc 2.19: */ _DEFAULT_SOURCE
38 || /* glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
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41 The j0() and j1() functions return Bessel functions of x of the first
42 kind of orders 0 and 1, respectively. The jn() function returns the
43 Bessel function of x of the first kind of order n.
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45 The j0f(), j1f(), and jnf(), functions are versions that take and re‐
46 turn float values. The j0l(), j1l(), and jnl() functions are versions
47 that take and return long double values.
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50 On success, these functions return the appropriate Bessel value of the
51 first kind for x.
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53 If x is a NaN, a NaN is returned.
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55 If x is too large in magnitude, or the result underflows, a range error
56 occurs, and the return value is 0.
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59 See math_error(7) for information on how to determine whether an error
60 has occurred when calling these functions.
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62 The following errors can occur:
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64 Range error: result underflow, or x is too large in magnitude
65 errno is set to ERANGE.
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67 These functions do not raise exceptions for fetestexcept(3).
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70 For an explanation of the terms used in this section, see at‐
71 tributes(7).
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73 ┌────────────────────────────────────────────┬───────────────┬─────────┐
74 │Interface │ Attribute │ Value │
75 ├────────────────────────────────────────────┼───────────────┼─────────┤
76 │j0(), j0f(), j0l() │ Thread safety │ MT-Safe │
77 ├────────────────────────────────────────────┼───────────────┼─────────┤
78 │j1(), j1f(), j1l() │ Thread safety │ MT-Safe │
79 ├────────────────────────────────────────────┼───────────────┼─────────┤
80 │jn(), jnf(), jnl() │ Thread safety │ MT-Safe │
81 └────────────────────────────────────────────┴───────────────┴─────────┘
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84 j0()
85 j1()
86 jn() POSIX.1-2008.
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88 Others:
89 BSD.
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92 j0()
93 j1()
94 jn() SVr4, 4.3BSD, POSIX.1-2001, POSIX.1-2008.
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96 Others:
97 BSD.
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100 There are errors of up to 2e-16 in the values returned by j0(), j1(),
101 and jn() for values of x between -8 and 8.
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104 y0(3)
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108Linux man-pages 6.05 2023-07-20 j0(3)