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>
5 .\" Permission is granted to make and distribute verbatim copies of this
6 .\" manual provided the copyright notice and this permission notice are
7 .\" preserved on all copies.
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15 .\" manual page may be incorrect or out-of-date.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
23 .\" the source, must acknowledge the copyright and authors of this work.
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 2008-08-05 "" "Linux Programmer's Manual"
37 .\"O log1p, log1pf, log1pl \- logarithm of 1 plus argument
38 log1p, log1pf, log1pl \- °ú¤¿ô¤Ë 1 ¤ò²Ã¤¨¤¿ÃͤÎÂпô
44 .BI "double log1p(double " x );
46 .BI "float log1pf(float " x );
48 .BI "long double log1pl(long double " x );
51 .\"O Link with \fI\-lm\fP.
52 \fI\-lm\fP ¤Ç¥ê¥ó¥¯¤¹¤ë¡£
55 .\"O Feature Test Macro Requirements for glibc (see
56 .\"O .BR feature_test_macros (7)):
57 glibc ¸þ¤±¤Îµ¡Ç½¸¡ºº¥Þ¥¯¥í¤ÎÍ×·ï
58 .RB ( feature_test_macros (7)
64 _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 500 || _ISOC99_SOURCE; or
69 _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE; or
75 .\"O returns a value equivalent to
77 ¤Ï°Ê²¼¤ÈÅù²Á¤ÊÃͤòÊÖ¤¹¡£
83 .\"O It is computed in a way
84 .\"O that is accurate even if the value of \fIx\fP is near zero.
85 \fIx\fP ¤ÎÃͤ¬ 0 ¤Ë¶á¤¤¾ì¹ç¤Ç¤âÀµ³Î¤Ë·×»»¤Ç¤¤ëÊýË¡¤¬ÍѤ¤¤é¤ì¤ë¡£
88 .\"O On success, these functions return the natural logarithm of
89 .\"O .IR "(1\ +\ x)" .
90 À®¸ù¤¹¤ë¤È¡¢¤³¤ì¤é¤Î´Ø¿ô¤Ï
97 .\"O a NaN is returned.
99 ¤¬ NaN ¤Î¾ì¹ç¡¢NaN ¤¬ÊÖ¤µ¤ì¤ë¡£
103 .\"O is positive infinity, positive infinity is returned.
105 ¤¬Àµ¤Î̵¸ÂÂç¤Î¾ì¹ç¡¢Àµ¤Î̵¸ÂÂ礬ÊÖ¤µ¤ì¤ë¡£
109 .\"O is \-1, a pole error occurs,
110 .\"O and the functions return
111 .\"O .RB - HUGE_VAL ,
112 .\"O .RB - HUGE_VALF ,
114 .\"O .RB - HUGE_VALL ,
117 ¤¬ \-1 ¤Î¾ì¹ç¡¢¶Ë¥¨¥é¡¼ (pole error) ¤¬È¯À¸¤·¡¢
126 .\"O is less than \-1 (including negative infinity),
127 .\"O a domain error occurs,
128 .\"O and a NaN (not a number) is returned.
130 ¤¬ \-1 ¤è¤ê¾®¤µ¤¤¾ì¹ç (Éé¤Î̵¸ÂÂç¤â´Þ¤à)¡¢
131 Îΰ襨¥é¡¼ (domain error) ¤¬È¯À¸¤·¡¢
132 NaN (not a number) ¤¬ÊÖ¤µ¤ì¤ë¡£
133 .\" POSIX.1 specifies a possible range error if x is subnormal
134 .\" glibc 2.8 doesn't do this
138 .\"O .BR math_error (7)
139 .\"O for information on how to determine whether an error has occurred
140 .\"O when calling these functions.
141 ¤³¤ì¤é¤Î´Ø¿ô¤ò¸Æ¤Ó½Ð¤·¤¿ºÝ¤Ë¥¨¥é¡¼¤¬È¯À¸¤·¤¿¤«¤ÎȽÄêÊýË¡¤Ë¤Ä¤¤¤Æ¤Î¾ðÊó¤Ï
145 .\"O The following errors can occur:
146 °Ê²¼¤Î¥¨¥é¡¼¤¬È¯À¸¤¹¤ë²ÄǽÀ¤¬¤¢¤ë¡£
148 .\"O Domain error: \fIx\fP is less than \-1
149 Îΰ襨¥é¡¼ (domain error): \fIx\fP ¤¬ \-1 ¤è¤ê¾®¤µ¤¤
153 .\"O An invalid floating-point exception
154 .\"O .RB ( FE_INVALID )
156 ÉÔÀµ (invalid) ÉâÆ°¾®¿ôÅÀÎã³°
160 .\"O Pole error: \fIx\fP is \-1
161 ¶Ë¥¨¥é¡¼ (pole error): \fIx\fP ¤¬ \-1 ¤Ç¤¢¤ë
165 .\"O A divide-by-zero floating-point exception
166 .\"O .RB ( FE_DIVBYZERO )
168 0 ¤Ë¤è¤ë½ü»» (divide-by-zero) ÉâÆ°¾®¿ôÅÀÎã³°
172 .\"O These functions do not set
177 .\" FIXME . Is it intentional that these functions do not set errno?
178 .\" log(), log2(), log10() do set errno
179 .\" Bug raised: http://sources.redhat.com/bugzilla/show_bug.cgi?id=6792
180 .\"O .SH "CONFORMING TO"