man3/j0.3

   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>
   4 .\"
   5 .\" %%%LICENSE_START(VERBATIM)
   6 .\" Permission is granted to make and distribute verbatim copies of this
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  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.
  14 .\"
  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  16 .\" manual page may be incorrect or out-of-date.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,
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  23 .\" Formatted or processed versions of this manual, if unaccompanied by
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  25 .\" %%%LICENSE_END
  26 .\"
  27 .\" References consulted:
  28 .\"     Linux libc source code
  29 .\"     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
  30 .\"     386BSD man pages
  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
  35 .\"
  36 .TH J0 3  2017-09-15 "" "Linux Programmer's Manual"
  37 .SH NAME
  38 j0, j0f, j0l, j1, j1f, j1l, jn, jnf, jnl \-
  39 Bessel functions of the first kind
  40 .SH SYNOPSIS
  41 .nf
  42 .B #include <math.h>
  43 .PP
  44 .BI "double j0(double " x );
  45 .BI "double j1(double " x );
  46 .BI "double jn(int " n ", double " x );
  47 .PP
  48 .BI "float j0f(float " x );
  49 .BI "float j1f(float " x );
  50 .BI "float jnf(int " n ", float " x );
  51 .PP
  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 );
  55 .fi
  56 .PP
  57 Link with \fI\-lm\fP.
  58 .PP
  59 .in -4n
  60 Feature Test Macro Requirements for glibc (see
  61 .BR feature_test_macros (7)):
  62 .in
  63 .PP
  64 .ad l
  65 .BR j0 (),
  66 .BR j1 (),
  67 .BR jn ():
  68 .RS 4
  69 _XOPEN_SOURCE
  70     || /* Since glibc 2.19: */ _DEFAULT_SOURCE
  71     || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
  72 .RE
  73 .br
  74 .BR j0f (),
  75 .BR j0l (),
  76 .BR j1f (),
  77 .BR j1l (),
  78 .BR jnf (),
  79 .BR jnl ():
  80 .RS 4
  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
  85 .RE
  86 .ad b
  87 .SH DESCRIPTION
  88 The
  89 .BR j0 ()
  90 and
  91 .BR j1 ()
  92 functions return Bessel functions of
  93 .I x
  94 of the first kind of orders 0 and 1, respectively.
  95 The
  96 .BR jn ()
  97 function
  98 returns the Bessel function of
  99 .I x
 100 of the first kind of order
 101 .IR n .
 102 .PP
 103 The
 104 .BR j0f (),
 105 .BR j1f (),
 106 and
 107 .BR jnf (),
 108 functions are versions that take and return
 109 .I float
 110 values.
 111 The
 112 .BR j0l (),
 113 .BR j1l (),
 114 and
 115 .BR jnl ()
 116 functions are versions that take and return
 117 .I "long double"
 118 values.
 119 .SH RETURN VALUE
 120 On success, these functions return the appropriate
 121 Bessel value of the first kind for
 122 .IR x .
 123 .PP
 124 If
 125 .I x
 126 is a NaN, a NaN is returned.
 127 .PP
 128 If
 129 .I x
 130 is too large in magnitude,
 131 or the result underflows,
 132 a range error occurs,
 133 and the return value is 0.
 134 .SH ERRORS
 135 See
 136 .BR math_error (7)
 137 for information on how to determine whether an error has occurred
 138 when calling these functions.
 139 .PP
 140 The following errors can occur:
 141 .TP
 142 Range error: result underflow, or \fIx\fP is too large in magnitude
 143 .I errno
 144 is set to
 145 .BR ERANGE .
 146 .PP
 147 These functions do not raise exceptions for
 148 .BR fetestexcept (3).
 149 .\" e.g., j0(1.5e16)
 150 .\" This is intentional.
 151 .\" See http://sources.redhat.com/bugzilla/show_bug.cgi?id=6805
 152 .SH ATTRIBUTES
 153 For an explanation of the terms used in this section, see
 154 .BR attributes (7).
 155 .TS
 156 allbox;
 157 lb lb lb
 158 l l l.
 159 Interface       Attribute       Value
 160 T{
 161 .BR j0 (),
 162 .BR j0f (),
 163 .BR j0l ()
 164 T}      Thread safety   MT-Safe
 165 T{
 166 .BR j1 (),
 167 .BR j1f (),
 168 .BR j1l ()
 169 T}      Thread safety   MT-Safe
 170 T{
 171 .BR jn (),
 172 .BR jnf (),
 173 .BR jnl ()
 174 T}      Thread safety   MT-Safe
 175 .TE
 176 .SH CONFORMING TO
 177 The functions returning
 178 .I double
 179 conform to SVr4, 4.3BSD,
 180 POSIX.1-2001, and POSIX.1-2008.
 181 The others are nonstandard functions that also exist on the BSDs.
 182 .SH BUGS
 183 There are errors of up to 2e\-16 in the values returned by
 184 .BR j0 (),
 185 .BR j1 ()
 186 and
 187 .BR jn ()
 188 for values of
 189 .I x
 190 between \-8 and 8.
 191 .SH SEE ALSO
 192 .BR y0 (3)