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.TH CPROJ 3M "Jul 12, 2006" "SunOS 5.11" "Mathematical Library Functions"
.SH NAME
cproj, cprojf, cprojl \- complex projection functions
.SH SYNOPSIS
.LP
.nf
c99 [ \fIflag\fR... ] \fIfile\fR... \fB-lm\fR [ \fIlibrary\fR... ]
#include <complex.h>

\fBdouble complex\fR \fBcproj\fR(\fBdouble complex\fR \fIz\fR);
.fi

.LP
.nf
\fBfloat complex\fR \fBcprojf\fR(\fBfloat complex\fR \fIz\fR);
.fi

.LP
.nf
\fBlong double complex\fR \fBcprojl\fR(\fBlong double complex\fR \fIz\fR);
.fi

.SH DESCRIPTION
.sp
.LP
These functions compute a projection of \fIz\fR onto the Riemann sphere:
\fIz\fR projects to \fIz\fR, except that all complex infinities (even those
with one infinite part and one NaN part) project to positive infinity on the
real axis. If \fIz\fR has an infinite part, then \fBcproj\fR(\fIz\fR) is
equivalent to:
.sp
.in +2
.nf
INFINITY + I * copysign(0.0, cimag(z))
.fi
.in -2

.SH RETURN VALUES
.sp
.LP
These functions return the value of the projection onto the Riemann sphere.
.SH ERRORS
.sp
.LP
No errors are defined.
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
tab(	) box;
cw(2.75i) |cw(2.75i)
lw(2.75i) |lw(2.75i)
.
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	Standard
_
MT-Level	MT-Safe
.TE

.SH SEE ALSO
.sp
.LP
\fBcarg\fR(3M), \fBcimag\fR(3M), \fBcomplex.h\fR(3HEAD), \fBconj\fR(3M),
\fBcreal\fR(3M), \fBattributes\fR(5), \fBstandards\fR(5)