xref: /minix3/lib/libm/complex/cproj.3 (revision 84d9c625bfea59e274550651111ae9edfdc40fbd)
1.\" $NetBSD: cproj.3,v 1.4 2012/12/27 21:34:10 wiz Exp $
2.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
3.Dd December 27, 2012
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.Sh DESCRIPTION
20These functions compute a projection of
21.Ar z
22onto the Riemann sphere:
23.Ar z
24projects to
25.Ar z ,
26except that all complex infinities (even those
27with one infinite part and one NaN part) project to positive infinity on the
28real axis.
29If
30.Ar z
31has an infinite part, then
32.Fn cproj
33shall be equivalent to:
34.Bd -literal -offset indent
35INFINITY + I * copysign(0.0, cimag(z))
36.Ed
37.Sh RETURN VALUES
38These functions return the value of the projection onto the Riemann sphere.
39.Sh ERRORS
40No errors are defined.
41.Sh SEE ALSO
42.Xr carg 3 ,
43.Xr cimag 3 ,
44.Xr conj 3 ,
45.Xr creal 3 ,
46.St -p1003.1-2001
47.Aq Pa complex.h
48.Sh COPYRIGHT
49Portions of this text are reprinted and reproduced in electronic form
50from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
51-- Portable Operating System Interface (POSIX), The Open Group Base
52Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
53Electrical and Electronics Engineers, Inc and The Open Group.
54In the
55event of any discrepancy between this version and the original IEEE and
56The Open Group Standard, the original IEEE and The Open Group Standard
57is the referee document.
58The original Standard can be obtained online at
59http://www.opengroup.org/unix/online.html .
60