man3/cproj.3

   1 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
   2 .\"
   3 .\" SPDX-License-Identifier: GPL-1.0-or-later
   4 .\"
   5 .TH cproj 3 (date) "Linux man-pages (unreleased)"
   6 .SH NAME
   7 cproj, cprojf, cprojl \- project into Riemann Sphere
   8 .SH LIBRARY
   9 Math library
  10 .RI ( libm ", " \-lm )
  11 .SH SYNOPSIS
  12 .nf
  13 .B #include <complex.h>
  14 .PP
  15 .BI "double complex cproj(double complex " z ");"
  16 .BI "float complex cprojf(float complex " z ");"
  17 .BI "long double complex cprojl(long double complex " z ");"
  18 .fi
  19 .SH DESCRIPTION
  20 These functions project a point in the plane onto the surface of a
  21 Riemann Sphere, the one-point compactification of the complex plane.
  22 Each finite point
  23 .I z
  24 projects to
  25 .I z
  26 itself.
  27 Every complex infinite value is projected to a single infinite value,
  28 namely to positive infinity on the real axis.
  29 .SH VERSIONS
  30 These functions first appeared in glibc in version 2.1.
  31 .SH ATTRIBUTES
  32 For an explanation of the terms used in this section, see
  33 .BR attributes (7).
  34 .ad l
  35 .nh
  36 .TS
  37 allbox;
  38 lbx lb lb
  39 l l l.
  40 Interface       Attribute       Value
  41 T{
  42 .BR cproj (),
  43 .BR cprojf (),
  44 .BR cprojl ()
  45 T}      Thread safety   MT-Safe
  46 .TE
  47 .hy
  48 .ad
  49 .sp 1
  50 .SH STANDARDS
  51 C99, POSIX.1-2001, POSIX.1-2008.
  52 .SH NOTES
  53 In glibc 2.11 and earlier, the implementation does something different
  54 (a
  55 .I stereographic
  56 projection onto a Riemann Sphere).
  57 .\" http://sources.redhat.com/bugzilla/show_bug.cgi?id=10401
  58 .SH SEE ALSO
  59 .BR cabs (3),
  60 .BR complex (7)