man3/exp2.3

   1 .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
   2 .\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
   3 .\"     <mtk.manpages@gmail.com>
   4 .\"
   5 .\" %%%LICENSE_START(VERBATIM)
   6 .\" Permission is granted to make and distribute verbatim copies of this
   7 .\" manual provided the copyright notice and this permission notice are
   8 .\" preserved on all copies.
   9 .\"
  10 .\" Permission is granted to copy and distribute modified versions of this
  11 .\" manual under the conditions for verbatim copying, provided that the
  12 .\" entire resulting derived work is distributed under the terms of a
  13 .\" permission notice identical to this one.
  14 .\"
  15 .\" Since the Linux kernel and libraries are constantly changing, this
  16 .\" manual page may be incorrect or out-of-date.  The author(s) assume no
  17 .\" responsibility for errors or omissions, or for damages resulting from
  18 .\" the use of the information contained herein.  The author(s) may not
  19 .\" have taken the same level of care in the production of this manual,
  20 .\" which is licensed free of charge, as they might when working
  21 .\" professionally.
  22 .\"
  23 .\" Formatted or processed versions of this manual, if unaccompanied by
  24 .\" the source, must acknowledge the copyright and authors of this work.
  25 .\" %%%LICENSE_END
  26 .\"
  27 .\" References consulted:
  28 .\"     Linux libc source code
  29 .\"     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
  30 .\"     386BSD man pages
  31 .\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu)
  32 .\" Modified 1995-08-14 by Arnt Gulbrandsen <agulbra@troll.no>
  33 .\" Modified 2002-07-27 by Walter Harms
  34 .\"     (walter.harms@informatik.uni-oldenburg.de)
  35 .\"
  36 .TH EXP2 3  2016-03-15  "" "Linux Programmer's Manual"
  37 .SH NAME
  38 exp2, exp2f, exp2l \- base-2 exponential function
  39 .SH SYNOPSIS
  40 .nf
  41 .B #include <math.h>
  42 .PP
  43 .BI "double exp2(double " x );
  44 .br
  45 .BI "float exp2f(float " x );
  46 .br
  47 .BI "long double exp2l(long double " x );
  48 .fi
  49 .PP
  50 Link with \fI\-lm\fP.
  51 .PP
  52 .in -4n
  53 Feature Test Macro Requirements for glibc (see
  54 .BR feature_test_macros (7)):
  55 .in
  56 .PP
  57 .ad l
  58 .BR exp2 (),
  59 .BR exp2f (),
  60 .BR exp2l ():
  61 .RS 4
  62 _ISOC99_SOURCE || _POSIX_C_SOURCE\ >=\ 200112L
  63 .RE
  64 .ad b
  65 .SH DESCRIPTION
  66 These functions return the value of 2 raised to the power of
  67 .IR x .
  68 .SH RETURN VALUE
  69 On success, these functions return the base-2 exponential value of
  70 .IR x .
  71
  72 For various special cases, including the handling of infinity and NaN,
  73 as well as overflows and underflows, see
  74 .BR exp (3).
  75 .SH ERRORS
  76 See
  77 .BR math_error (7)
  78 for information on how to determine whether an error has occurred
  79 when calling these functions.
  80
  81 For a discussion of the errors that can occur for these functions, see
  82 .BR exp (3).
  83 .SH VERSIONS
  84 These functions first appeared in glibc in version 2.1.
  85 .SH ATTRIBUTES
  86 For an explanation of the terms used in this section, see
  87 .BR attributes (7).
  88 .TS
  89 allbox;
  90 lbw24 lb lb
  91 l l l.
  92 Interface       Attribute       Value
  93 T{
  94 .BR exp2 (),
  95 .BR exp2f (),
  96 .BR exp2l ()
  97 T}      Thread safety   MT-Safe
  98 .TE
  99 .SH CONFORMING TO
 100 C99, POSIX.1-2001, POSIX.1-2008.
 101
 102 The variant returning
 103 .I double
 104 also conforms to
 105 SVr4, 4.3BSD.
 106 .SH SEE ALSO
 107 .BR cbrt (3),
 108 .BR cexp2 (3),
 109 .BR exp (3),
 110 .BR exp10 (3),
 111 .BR sqrt (3)