.\" $NetBSD: cproj.3,v 1.5 2017/09/27 09:20:27 maya Exp $
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
.Dd September 27, 2017
.Dt CPROJ 3
.Os
.Sh NAME
.Nm cproj ,
.Nm cprojf ,
.Nm cprojl
.Nd complex projection functions
.Sh SYNOPSIS
.In complex.h
.Ft double
.Fn cproj "double complex z"
.Ft float
.Fn cprojf "float complex z"
.Ft long double
.Fn cprojl "long double complex z"
.In tgmath.h
.Ft complex-floating
.Fn cproj "complex-floating z"
.Sh DESCRIPTION
These functions compute a projection of
.Ar z
onto the Riemann sphere:
.Ar z
projects to
.Ar z ,
except that all complex infinities (even those
with one infinite part and one NaN part) project to positive infinity on the
real axis.
If
.Ar z
has an infinite part, then
.Fn cproj
shall be equivalent to:
.Bd -literal -offset indent
INFINITY + I * copysign(0.0, cimag(z))
.Ed
.Sh RETURN VALUES
These functions return the value of the projection onto the Riemann sphere.
.Sh ERRORS
No errors are defined.
.Sh SEE ALSO
.Xr carg 3 ,
.Xr cimag 3 ,
.Xr conj 3 ,
.Xr creal 3 ,
.St -p1003.1-2001
.Aq Pa complex.h
.Sh COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document.
The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .