xref: /netbsd-src/lib/libm/complex/cproj.3 (revision 411564dc9ac78e3b850fc18d857ae90e152b8fb4)
1.\" $NetBSD: cproj.3,v 1.5 2017/09/27 09:20:27 maya Exp $
2.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
3.Dd September 27, 2017
4.Dt CPROJ 3
5.Os
6.Sh NAME
7.Nm cproj ,
8.Nm cprojf ,
9.Nm cprojl
10.Nd complex projection functions
11.Sh SYNOPSIS
12.In complex.h
13.Ft double
14.Fn cproj "double complex z"
15.Ft float
16.Fn cprojf "float complex z"
17.Ft long double
18.Fn cprojl "long double complex z"
19.In tgmath.h
20.Ft complex-floating
21.Fn cproj "complex-floating z"
22.Sh DESCRIPTION
23These functions compute a projection of
24.Ar z
25onto the Riemann sphere:
26.Ar z
27projects to
28.Ar z ,
29except that all complex infinities (even those
30with one infinite part and one NaN part) project to positive infinity on the
31real axis.
32If
33.Ar z
34has an infinite part, then
35.Fn cproj
36shall be equivalent to:
37.Bd -literal -offset indent
38INFINITY + I * copysign(0.0, cimag(z))
39.Ed
40.Sh RETURN VALUES
41These functions return the value of the projection onto the Riemann sphere.
42.Sh ERRORS
43No errors are defined.
44.Sh SEE ALSO
45.Xr carg 3 ,
46.Xr cimag 3 ,
47.Xr conj 3 ,
48.Xr creal 3 ,
49.St -p1003.1-2001
50.Aq Pa complex.h
51.Sh COPYRIGHT
52Portions of this text are reprinted and reproduced in electronic form
53from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
54-- Portable Operating System Interface (POSIX), The Open Group Base
55Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
56Electrical and Electronics Engineers, Inc and The Open Group.
57In the
58event of any discrepancy between this version and the original IEEE and
59The Open Group Standard, the original IEEE and The Open Group Standard
60is the referee document.
61The original Standard can be obtained online at
62http://www.opengroup.org/unix/online.html .
63