1 .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
2 .\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
3 .\" <mtk.manpages@gmail.com>
5 .\" %%%LICENSE_START(VERBATIM)
6 .\" Permission is granted to make and distribute verbatim copies of this
7 .\" manual provided the copyright notice and this permission notice are
8 .\" preserved on all copies.
10 .\" Permission is granted to copy and distribute modified versions of this
11 .\" manual under the conditions for verbatim copying, provided that the
12 .\" entire resulting derived work is distributed under the terms of a
13 .\" permission notice identical to this one.
15 .\" Since the Linux kernel and libraries are constantly changing, this
16 .\" manual page may be incorrect or out-of-date. The author(s) assume no
17 .\" responsibility for errors or omissions, or for damages resulting from
18 .\" the use of the information contained herein. The author(s) may not
19 .\" have taken the same level of care in the production of this manual,
20 .\" which is licensed free of charge, as they might when working
23 .\" Formatted or processed versions of this manual, if unaccompanied by
24 .\" the source, must acknowledge the copyright and authors of this work.
27 .\" References consulted:
28 .\" Linux libc source code
29 .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
31 .\" Modified Sat Jul 24 19:08:17 1993 by Rik Faith (faith@cs.unc.edu)
32 .\" Modified 2002-08-25, aeb
33 .\" Modified 2004-11-12 as per suggestion by Fabian Kreutz/AEB
34 .\" 2008-07-24, mtk, moved yxx() material into separate y0.3 page
36 .TH J0 3 2017-09-15 "" "Linux Programmer's Manual"
38 j0, j0f, j0l, j1, j1f, j1l, jn, jnf, jnl \-
39 Bessel functions of the first kind
44 .BI "double j0(double " x );
45 .BI "double j1(double " x );
46 .BI "double jn(int " n ", double " x );
48 .BI "float j0f(float " x );
49 .BI "float j1f(float " x );
50 .BI "float jnf(int " n ", float " x );
52 .BI "long double j0l(long double " x );
53 .BI "long double j1l(long double " x );
54 .BI "long double jnl(int " n ", long double " x );
60 Feature Test Macro Requirements for glibc (see
61 .BR feature_test_macros (7)):
70 || /* Since glibc 2.19: */ _DEFAULT_SOURCE
71 || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
81 _XOPEN_SOURCE \ >=\ 600
82 || (_ISOC99_SOURCE && _XOPEN_SOURCE)
83 || /* Since glibc 2.19: */ _DEFAULT_SOURCE
84 || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
92 functions return Bessel functions of
94 of the first kind of orders 0 and 1, respectively.
98 returns the Bessel function of
100 of the first kind of order
108 functions are versions that take and return
116 functions are versions that take and return
120 On success, these functions return the appropriate
121 Bessel value of the first kind for
126 is a NaN, a NaN is returned.
130 is too large in magnitude,
131 or the result underflows,
132 a range error occurs,
133 and the return value is 0.
137 for information on how to determine whether an error has occurred
138 when calling these functions.
140 The following errors can occur:
142 Range error: result underflow, or \fIx\fP is too large in magnitude
146 .\" An underflow floating-point exception
147 .\" .RB ( FE_UNDERFLOW )
150 These functions do not raise exceptions for
151 .BR fetestexcept (3).
152 .\" FIXME . Is it intentional that these functions do not raise exceptions?
154 .\" Bug raised: http://sources.redhat.com/bugzilla/show_bug.cgi?id=6805
156 For an explanation of the terms used in this section, see
162 Interface Attribute Value
167 T} Thread safety MT-Safe
172 T} Thread safety MT-Safe
177 T} Thread safety MT-Safe
180 The functions returning
182 conform to SVr4, 4.3BSD,
183 POSIX.1-2001, and POSIX.1-2008.
184 The others are nonstandard functions that also exist on the BSDs.
186 There are errors of up to 2e\-16 in the values returned by