man3/cproj.3

   1 '\" t
   2 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
   3 .\"
   4 .\" SPDX-License-Identifier: GPL-1.0-or-later
   5 .\"
   6 .TH cproj 3 (date) "Linux man-pages (unreleased)"
   7 .SH NAME
   8 cproj, cprojf, cprojl \- project into Riemann Sphere
   9 .SH LIBRARY
  10 Math library
  11 .RI ( libm ", " \-lm )
  12 .SH SYNOPSIS
  13 .nf
  14 .B #include <complex.h>
  15 .PP
  16 .BI "double complex cproj(double complex " z ");"
  17 .BI "float complex cprojf(float complex " z ");"
  18 .BI "long double complex cprojl(long double complex " z ");"
  19 .fi
  20 .SH DESCRIPTION
  21 These functions project a point in the plane onto the surface of a
  22 Riemann Sphere, the one-point compactification of the complex plane.
  23 Each finite point
  24 .I z
  25 projects to
  26 .I z
  27 itself.
  28 Every complex infinite value is projected to a single infinite value,
  29 namely to positive infinity on the real axis.
  30 .SH ATTRIBUTES
  31 For an explanation of the terms used in this section, see
  32 .BR attributes (7).
  33 .TS
  34 allbox;
  35 lbx lb lb
  36 l l l.
  37 Interface       Attribute       Value
  38 T{
  39 .na
  40 .nh
  41 .BR cproj (),
  42 .BR cprojf (),
  43 .BR cprojl ()
  44 T}      Thread safety   MT-Safe
  45 .TE
  46 .sp 1
  47 .SH STANDARDS
  48 C11, POSIX.1-2008.
  49 .SH HISTORY
  50 glibc 2.1.
  51 C99, POSIX.1-2001.
  52 .PP
  53 In glibc 2.11 and earlier, the implementation does something different
  54 (a
  55 .I stereographic
  56 projection onto a Riemann Sphere).
  57 .\" https://www.sourceware.org/bugzilla/show_bug.cgi?id=10401
  58 .SH SEE ALSO
  59 .BR cabs (3),
  60 .BR complex (7)