1 .\" Copyright 2008, Linux Foundation, written by Michael Kerrisk
2 .\" <mtk.manpages@gmail.com>
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13 .\" Since the Linux kernel and libraries are constantly changing, this
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18 .\" which is licensed free of charge, as they might when working
21 .\" Formatted or processed versions of this manual, if unaccompanied by
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24 .\" Japanese Version Copyright (c) 2008 Akihiro MOTOKI
25 .\" all rights reserved.
26 .\" Translated 2008-09-15, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
28 .\"WORD: subnormal 非正規化の
30 .TH ERFC 3 2010-09-20 "GNU" "Linux Programmer's Manual"
32 erfc, erfcf, erfcl \- 相補誤差関数
37 .BI "double erfc(double " x );
38 .BI "float erfcf(float " x );
39 .BI "long double erfcl(long double " x );
46 .RB ( feature_test_macros (7)
53 _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE || _ISOC99_SOURCE ||
54 _POSIX_C_SOURCE\ >=\ 200112L;
63 _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE ||
64 _POSIX_C_SOURCE\ >=\ 200112L;
74 の相補誤差関数、つまり 1.0 \- erf(x) を返す。
85 が +0 か \-0 の場合、1 が返される。
93 関数の結果がアンダーフローし、表現できない値となる場合は、
97 表現できる値 (つまり非正規化数 (subnormal)) となる場合は、
98 .\" 例えば x86-32 での erfc(27)
99 その値が返され、範囲エラー (range error) が発生する。
101 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
107 範囲エラー: 結果のアンダーフロー (結果が非正規化数)
118 .\" FIXME . Is it intentional that these functions do not set errno?
119 .\" Bug raised: http://sources.redhat.com/bugzilla/show_bug.cgi?id=6785
123 版の関数は SVr4, 4.3BSD にも準拠している。
128 が大きな値の場合に (erf(x) の値は 1 に近付いていくことで)
129 1-erf(x) の計算において精度が失われるのを避けるためである。