exp2(3) [v7 man page]

EXP2(3) 						     Linux Programmer's Manual							   EXP2(3)

NAME

       exp2, exp2f, exp2l - base-2 exponential function

SYNOPSIS

       #include <math.h>

       double exp2(double x);
       float exp2f(float x);
       long double exp2l(long double x);

       Link with -lm.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       exp2(), exp2f(), exp2l():
	   _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L

DESCRIPTION

       These functions return the value of 2 raised to the power of x.

RETURN VALUE

       On success, these functions return the base-2 exponential value of x.

       For various special cases, including the handling of infinity and NaN, as well as overflows and underflows, see exp(3).

ERRORS

       See math_error(7) for information on how to determine whether an error has occurred when calling these functions.

       For a discussion of the errors that can occur for these functions, see exp(3).

VERSIONS

       These functions first appeared in glibc in version 2.1.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       +-------------------------+---------------+---------+
       |Interface		 | Attribute	 | Value   |
       +-------------------------+---------------+---------+
       |exp2(), exp2f(), exp2l() | Thread safety | MT-Safe |
       +-------------------------+---------------+---------+
CONFORMING TO

       C99, POSIX.1-2001, POSIX.1-2008.

       The variant returning double also conforms to SVr4, 4.3BSD.

SEE ALSO

       cbrt(3), cexp2(3), exp(3), exp10(3), sqrt(3)

COLOPHON

       This  page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

								    2017-09-15								   EXP2(3)

exp2(3M)						  Mathematical Library Functions						  exp2(3M)

NAME

       exp2, exp2f, exp2l - exponential base 2 functions

SYNOPSIS

       cc [ flag... ] file... -lm [ library... ]
       #include <math.h>

       double exp2(double x);

       float exp2f(float x);

       long double exp2l(long double x);

DESCRIPTION

       These functions compute the base-2 exponential of x.

RETURN VALUES

       Upon successful completion, these functions return 2**x.

       If  the	correct  value would cause overflow, a range error occurs and exp2(), exp2f(), and exp2l() return the value of the macro HUGE_VAL,
       HUGE_VALF, and HUGE_VALL, respectively.

       If x is NaN, a NaN is returned.

       If x is +-0, 1 is returned.

       If x is -Inf, +0 is returned.

       If x is +Inf, x is returned.

ERRORS

       These functions will fail if:

       Range Error     The result overflows.

		       If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, the overflow floating-point  exception  will	be
		       raised.

USAGE

       An  application	wanting  to  check  for  exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if
       fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception  has  been  raised.  An  application  should
       either examine the return value or check the floating point exception flags to detect exceptions.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       exp(3M), feclearexcept(3M), fetestexcept(3M), isnan(3M), log(3M), math.h(3HEAD), attributes(5), standards(5)

SunOS 5.10							    1 Sep 2002								  exp2(3M)