man3/cproj.3

   1 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
   2 .\"
   3 .\" %%%LICENSE_START(GPL_NOVERSION_ONELINE)
   4 .\" Distributed under GPL
   5 .\" %%%LICENSE_END
   6 .\"
   7 .TH CPROJ 3 2015-04-19 "" "Linux Programmer's Manual"
   8 .SH NAME
   9 cproj, cprojf, cprojl \- project into Riemann Sphere
  10 .SH SYNOPSIS
  11 .B #include <complex.h>
  12 .PP
  13 .BI "double complex cproj(double complex " z ");"
  14 .br
  15 .BI "float complex cprojf(float complex " z ");"
  16 .br
  17 .BI "long double complex cprojl(long double complex " z ");"
  18 .PP
  19 Link with \fI\-lm\fP.
  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 VERSIONS
  31 These functions first appeared in glibc in version 2.1.
  32 .SH ATTRIBUTES
  33 For an explanation of the terms used in this section, see
  34 .BR attributes (7).
  35 .TS
  36 allbox;
  37 lbw27 lb lb
  38 l l l.
  39 Interface       Attribute       Value
  40 T{
  41 .BR cproj (),
  42 .BR cprojf (),
  43 .BR cprojl ()
  44 T}      Thread safety   MT-Safe
  45 .TE
  46 .SH CONFORMING TO
  47 C99, POSIX.1-2001, POSIX.1-2008.
  48 .SH NOTES
  49 In glibc 2.11 and earlier, the implementation does something different
  50 (a
  51 .I stereographic
  52 projection onto a Riemann Sphere).
  53 .\" http://sources.redhat.com/bugzilla/show_bug.cgi?id=10401
  54 .SH SEE ALSO
  55 .BR cabs (3),
  56 .BR complex (7)