1 .\" Copyright 1995 Jim Van Zandt <jrv@vanzandt.mv.com>
2 .\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
3 .\" <mtk.manpages@gmail.com>
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6 .\" manual provided the copyright notice and this permission notice are
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9 .\" Permission is granted to copy and distribute modified versions of this
10 .\" manual under the conditions for verbatim copying, provided that the
11 .\" entire resulting derived work is distributed under the terms of a
12 .\" permission notice identical to this one.
14 .\" Since the Linux kernel and libraries are constantly changing, this
15 .\" manual page may be incorrect or out-of-date. The author(s) assume no
16 .\" responsibility for errors or omissions, or for damages resulting from
17 .\" the use of the information contained herein. The author(s) may not
18 .\" have taken the same level of care in the production of this manual,
19 .\" which is licensed free of charge, as they might when working
22 .\" Formatted or processed versions of this manual, if unaccompanied by
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25 .\" Modified 2002-07-27 by Walter Harms
26 .\" (walter.harms@informatik.uni-oldenburg.de)
28 .\" Japanese Version Copyright (c) 2003 Akihiro MOTOKI
29 .\" all rights reserved.
30 .\" Translated Wed Aug 6 00:35:20 JST 2003
31 .\" by Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
32 .\" Updated 2008-09-16, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
34 .TH LOG1P 3 2010-09-20 "" "Linux Programmer's Manual"
36 log1p, log1pf, log1pl \- 引き数に 1 を加えた値の対数
41 .BI "double log1p(double " x );
43 .BI "float log1pf(float " x );
45 .BI "long double log1pl(long double " x );
52 .RB ( feature_test_macros (7)
59 _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 500 ||
60 _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED || _ISOC99_SOURCE ||
61 _POSIX_C_SOURCE\ >=\ 200112L;
70 _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE ||
71 _POSIX_C_SOURCE\ >=\ 200112L;
85 \fIx\fP の値が 0 に近い場合でも正確に計算できる方法が用いられる。
98 が \-1 の場合、極エラー (pole error) が発生し、
106 が \-1 より小さい場合 (負の無限大も含む)、
107 領域エラー (domain error) が発生し、
108 NaN (not a number) が返される。
109 .\" POSIX.1 specifies a possible range error if x is subnormal
110 .\" glibc 2.8 doesn't do this
112 これらの関数を呼び出した際にエラーが発生したかの判定方法についての情報は
118 領域エラー (domain error): \fIx\fP が \-1 より小さい
126 極エラー (pole error): \fIx\fP が \-1 である
130 0 による除算 (divide-by-zero) 浮動小数点例外
137 .\" FIXME . Is it intentional that these functions do not set errno?
138 .\" log(), log2(), log10() do set errno
139 .\" Bug raised: http://sources.redhat.com/bugzilla/show_bug.cgi?id=6792