man3/creal.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 CREAL 3 2015-04-19 "" "Linux Programmer's Manual"
   8 .SH NAME
   9 creal, crealf, creall \- get real part of a complex number
  10 .SH SYNOPSIS
  11 .B #include <complex.h>
  12 .sp
  13 .BI "double creal(double complex " z );
  14 .br
  15 .BI "float crealf(float complex " z );
  16 .br
  17 .BI "long double creall(long double complex " z );
  18 .sp
  19 Link with \fI\-lm\fP.
  20 .SH DESCRIPTION
  21 These functions return the real part of the complex number
  22 .IR z .
  23 .LP
  24 One has:
  25 .nf
  26
  27     z = creal(z) + I * cimag(z)
  28 .fi
  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 .TS
  35 allbox;
  36 lbw27 lb lb
  37 l l l.
  38 Interface       Attribute       Value
  39 T{
  40 .BR creal (),
  41 .BR crealf (),
  42 .BR creall ()
  43 T}      Thread safety   MT-Safe
  44 .TE
  45 .SH CONFORMING TO
  46 C99, POSIX.1-2001, POSIX.1-2008.
  47 .SH NOTES
  48 The gcc supports also __real__.
  49 That is a GNU extension.
  50 .SH SEE ALSO
  51 .BR cabs (3),
  52 .BR cimag (3),
  53 .BR complex (7)