📄 complex.h.html
字号:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta name="generator" content="HTML Tidy, see www.w3.org"><meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><link type="text/css" rel="stylesheet" href="style.css"><!-- Generated by The Open Group's rhtm tool v1.2.1 --><!-- Copyright (c) 2001-2003 The Open Group, All Rights Reserved --><title><complex.h></title></head><body bgcolor="white"><script type="text/javascript" language="JavaScript" src="../jscript/codes.js"></script><basefont size="3"> <a name="<complex.h>"></a> <a name="tag_13_05"></a><!-- <complex.h> --> <!--header start--><center><font size="2">The Open Group Base Specifications Issue 6<br>IEEE Std 1003.1, 2003 Edition<br>Copyright © 2001-2003 The IEEE and The Open Group, All Rights reserved.</font></center><!--header end--><hr size="2" noshade><h4><a name="tag_13_05_01"></a>NAME</h4><blockquote>complex.h - complex arithmetic</blockquote><h4><a name="tag_13_05_02"></a>SYNOPSIS</h4><blockquote class="synopsis"><p><tt>#include <complex.h></tt></p></blockquote><h4><a name="tag_13_05_03"></a>DESCRIPTION</h4><blockquote><div class="box"><sup>[<a href="javascript:open_code('CX')">CX</a>]</sup> <img src="../images/opt-start.gif" alt="[Option Start]"border="0"> The functionality described on this reference page is aligned with the ISO C standard. Any conflict between therequirements described here and the ISO C standard is unintentional. This volume of IEEE Std 1003.1-2001 defers tothe ISO C standard. <img src="../images/opt-end.gif" alt="[Option End]" border="0"></div><p>The <i><complex.h></i> header shall define the following macros:</p><dl compact><dt>complex</dt><dd>Expands to <b>_Complex</b>.</dd><dt>_Complex_I</dt><dd>Expands to a constant expression of type <b>const float _Complex</b>, with the value of the imaginary unit (that is, a number<i>i</i> such that <i>i</i><small><sup>2</sup></small>=-1).</dd><dt>imaginary</dt><dd>Expands to <b>_Imaginary</b>.</dd><dt>_Imaginary_I</dt><dd>Expands to a constant expression of type <b>const float _Imaginary</b> with the value of the imaginary unit.</dd><dt>I</dt><dd>Expands to either _Imaginary_I or _Complex_I. If _Imaginary_I is not defined, I expands to _Complex_I.</dd></dl><p>The macros imaginary and _Imaginary_I shall be defined if and only if the implementation supports imaginary types.</p><p>An application may undefine and then, perhaps, redefine the complex, imaginary, and I macros.</p><p>The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.</p><pre><tt>double cabs(double complex);float cabsf(float complex);long double cabsl(long double complex);double complex cacos(double complex);float complex cacosf(float complex);double complex cacosh(double complex);float complex cacoshf(float complex);long double complex cacoshl(long double complex);long double complex cacosl(long double complex);double carg(double complex);float cargf(float complex);long double cargl(long double complex);double complex casin(double complex);float complex casinf(float complex);double complex casinh(double complex);float complex casinhf(float complex);long double complex casinhl(long double complex);long double complex casinl(long double complex);double complex catan(double complex);float complex catanf(float complex);double complex catanh(double complex);float complex catanhf(float complex);long double complex catanhl(long double complex);long double complex catanl(long double complex);double complex ccos(double complex);float complex ccosf(float complex);double complex ccosh(double complex);float complex ccoshf(float complex);long double complex ccoshl(long double complex);long double complex ccosl(long double complex);double complex cexp(double complex);float complex cexpf(float complex);long double complex cexpl(long double complex);double cimag(double complex);float cimagf(float complex);long double cimagl(long double complex);double complex clog(double complex);float complex clogf(float complex);long double complex clogl(long double complex);double complex conj(double complex);float complex conjf(float complex);long double complex conjl(long double complex);double complex cpow(double complex, double complex);float complex cpowf(float complex, float complex);long double complex cpowl(long double complex, long double complex);double complex cproj(double complex);float complex cprojf(float complex);long double complex cprojl(long double complex);double creal(double complex);float crealf(float complex);long double creall(long double complex);double complex csin(double complex);float complex csinf(float complex);double complex csinh(double complex);float complex csinhf(float complex);long double complex csinhl(long double complex);long double complex csinl(long double complex);double complex csqrt(double complex);float complex csqrtf(float complex);long double complex csqrtl(long double complex);double complex ctan(double complex);float complex ctanf(float complex);double complex ctanh(double complex);float complex ctanhf(float complex);long double complex ctanhl(long double complex);long double complex ctanl(long double complex);</tt></pre></blockquote><hr><div class="box"><em>The following sections are informative.</em></div><h4><a name="tag_13_05_04"></a>APPLICATION USAGE</h4><blockquote><p>Values are interpreted as radians, not degrees.</p></blockquote><h4><a name="tag_13_05_05"></a>RATIONALE</h4><blockquote><p>The choice of <i>I</i> instead of <i>i</i> for the imaginary unit concedes to the widespread use of the identifier <i>i</i> forother purposes. The application can use a different identifier, say <i>j</i>, for the imaginary unit by following the inclusion ofthe <i><complex.h></i> header with:</p><pre><tt>#undef I#define j _Imaginary_I</tt></pre><p>An <i>I</i> suffix to designate imaginary constants is not required, as multiplication by <i>I</i> provides a sufficientlyconvenient and more generally useful notation for imaginary terms. The corresponding real type for the imaginary unit is<b>float</b>, so that use of <i>I</i> for algorithmic or notational convenience will not result in widening types.</p><p>On systems with imaginary types, the application has the ability to control whether use of the macro I introduces an imaginarytype, by explicitly defining I to be _Imaginary_I or _Complex_I. Disallowing imaginary types is useful for some applicationsintended to run on implementations without support for such types.</p><p>The macro _Imaginary_I provides a test for whether imaginary types are supported.</p><p>The <i>cis</i>() function (<i>cos</i>(<i>x</i>) + <i>I</i>*<i>sin</i>(<i>x</i>)) was considered but rejected because itsimplementation is easy and straightforward, even though some implementations could compute sine and cosine more efficiently intandem.</p></blockquote><h4><a name="tag_13_05_06"></a>FUTURE DIRECTIONS</h4><blockquote><p>The following function names and the same names suffixed with <i>f</i> or <i>l</i> are reserved for future use, and may be addedto the declarations in the <i><complex.h></i> header.</p><blockquote><table cellpadding="3"><tr valign="top"><td align="left"><p class="tent"><br><i>cerf</i>()<br><i>cerfc</i>()<br><i>cexp2</i>()<br> </p></td><td align="left"><p class="tent"><br><i>cexpm1</i>()<br><i>clog10</i>()<br><i>clog1p</i>()<br> </p></td><td align="left"><p class="tent"><br><i>clog2</i>()<br><i>clgamma</i>()<br><i>ctgamma</i>()<br> </p></td></tr></table></blockquote></blockquote><h4><a name="tag_13_05_07"></a>SEE ALSO</h4><blockquote><p>The System Interfaces volume of IEEE Std 1003.1-2001, <a href="../functions/cabs.html"><i>cabs</i>()</a>, <a href="../functions/cacos.html"><i>cacos</i>()</a>, <a href="../functions/cacosh.html"><i>cacosh</i>()</a>, <a href="../functions/carg.html"><i>carg</i>()</a>, <a href="../functions/casin.html"><i>casin</i>()</a>, <a href="../functions/casinh.html"><i>casinh</i>()</a>, <a href="../functions/catan.html"><i>catan</i>()</a>, <a href="../functions/catanh.html"><i>catanh</i>()</a>, <a href="../functions/ccos.html"><i>ccos</i>()</a>, <a href="../functions/ccosh.html"><i>ccosh</i>()</a>, <a href="../functions/cexp.html"><i>cexp</i>()</a>, <a href="../functions/cimag.html"><i>cimag</i>()</a>, <a href="../functions/clog.html"><i>clog</i>()</a>, <a href="../functions/conj.html"><i>conj</i>()</a>, <a href="../functions/cpow.html"><i>cpow</i>()</a>, <a href="../functions/cproj.html"><i>cproj</i>()</a>, <a href="../functions/creal.html"><i>creal</i>()</a>, <a href="../functions/csin.html"><i>csin</i>()</a>, <a href="../functions/csinh.html"><i>csinh</i>()</a>, <a href="../functions/csqrt.html"><i>csqrt</i>()</a>, <a href="../functions/ctan.html"><i>ctan</i>()</a>, <a href="../functions/ctanh.html"><i>ctanh</i>()</a></p></blockquote><h4><a name="tag_13_05_08"></a>CHANGE HISTORY</h4><blockquote><p>First released in Issue 6. Included for alignment with the ISO/IEC 9899:1999 standard.</p></blockquote><div class="box"><em>End of informative text.</em></div><hr><hr size="2" noshade><center><font size="2"><!--footer start-->UNIX ® is a registered Trademark of The Open Group.<br>POSIX ® is a registered Trademark of The IEEE.<br>[ <a href="../mindex.html">Main Index</a> | <a href="../basedefs/contents.html">XBD</a> | <a href="../utilities/contents.html">XCU</a> | <a href="../functions/contents.html">XSH</a> | <a href="../xrat/contents.html">XRAT</a>]</font></center><!--footer end--><hr size="2" noshade></body></html>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -