jnf(3) - f34

1J0(3)                      Linux Programmer's Manual                     J0(3)
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NAME

6       j0,  j0f,  j0l,  j1,  j1f,  j1l, jn, jnf, jnl - Bessel functions of the
7       first kind
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SYNOPSIS

10       #include <math.h>
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12       double j0(double x);
13       double j1(double x);
14       double jn(int n, double x);
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16       float j0f(float x);
17       float j1f(float x);
18       float jnf(int n, float x);
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20       long double j0l(long double x);
21       long double j1l(long double x);
22       long double jnl(int n, long double x);
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24       Link with -lm.
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26   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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28       j0(), j1(), jn():
29           _XOPEN_SOURCE
30               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
31               || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
32       j0f(), j0l(), j1f(), j1l(), jnf(), jnl():
33           _XOPEN_SOURCE  >= 600
34               || (_ISOC99_SOURCE && _XOPEN_SOURCE)
35               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
36               || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
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DESCRIPTION

39       The j0() and j1() functions return Bessel functions of x of  the  first
40       kind  of  orders  0 and 1, respectively.  The jn() function returns the
41       Bessel function of x of the first kind of order n.
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43       The j0f(), j1f(), and jnf(), functions are versions that take  and  re‐
44       turn  float values.  The j0l(), j1l(), and jnl() functions are versions
45       that take and return long double values.
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RETURN VALUE

48       On success, these functions return the appropriate Bessel value of  the
49       first kind for x.
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51       If x is a NaN, a NaN is returned.
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53       If x is too large in magnitude, or the result underflows, a range error
54       occurs, and the return value is 0.
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ERRORS

57       See math_error(7) for information on how to determine whether an  error
58       has occurred when calling these functions.
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60       The following errors can occur:
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62       Range error: result underflow, or x is too large in magnitude
63              errno is set to ERANGE.
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65       These functions do not raise exceptions for fetestexcept(3).
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ATTRIBUTES

68       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
69       tributes(7).
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71       ┌───────────────────┬───────────────┬─────────┐
72       │Interface          │ Attribute     │ Value   │
73       ├───────────────────┼───────────────┼─────────┤
74       │j0(), j0f(), j0l() │ Thread safety │ MT-Safe │
75       ├───────────────────┼───────────────┼─────────┤
76       │j1(), j1f(), j1l() │ Thread safety │ MT-Safe │
77       ├───────────────────┼───────────────┼─────────┤
78       │jn(), jnf(), jnl() │ Thread safety │ MT-Safe │
79       └───────────────────┴───────────────┴─────────┘

CONFORMING TO

81       The functions returning double conform to SVr4,  4.3BSD,  POSIX.1-2001,
82       and POSIX.1-2008.  The others are nonstandard functions that also exist
83       on the BSDs.
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BUGS

86       There are errors of up to 2e-16 in the values returned by  j0(),  j1(),
87       and jn() for values of x between -8 and 8.
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COLOPHON

93       This  page  is  part of release 5.10 of the Linux man-pages project.  A
94       description of the project, information about reporting bugs,  and  the
95       latest     version     of     this    page,    can    be    found    at
96       https://www.kernel.org/doc/man-pages/.
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100                                  2020-12-21                             J0(3)