man3/creal.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 CREAL 3 2021-03-22 GNU "Linux Programmer's Manual"
   6 .SH NAME
   7 creal, crealf, creall \- get real part of a complex number
   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 creal(double complex " z );
  16 .BI "float crealf(float complex " z );
  17 .BI "long double creall(long double complex " z );
  18 .fi
  19 .SH DESCRIPTION
  20 These functions return the real part of the complex number
  21 .IR z .
  22 .PP
  23 One has:
  24 .PP
  25 .nf
  26     z = creal(z) + I * cimag(z)
  27 .fi
  28 .SH VERSIONS
  29 These functions first appeared in glibc in version 2.1.
  30 .SH ATTRIBUTES
  31 For an explanation of the terms used in this section, see
  32 .BR attributes (7).
  33 .ad l
  34 .nh
  35 .TS
  36 allbox;
  37 lbx lb lb
  38 l l l.
  39 Interface       Attribute       Value
  40 T{
  41 .BR creal (),
  42 .BR crealf (),
  43 .BR creall ()
  44 T}      Thread safety   MT-Safe
  45 .TE
  46 .hy
  47 .ad
  48 .sp 1
  49 .SH CONFORMING TO
  50 C99, POSIX.1-2001, POSIX.1-2008.
  51 .SH NOTES
  52 The gcc supports also __real__.
  53 That is a GNU extension.
  54 .SH SEE ALSO
  55 .BR cabs (3),
  56 .BR cimag (3),
  57 .BR complex (7)