exp2f man page on YellowDog

Man page or keyword search:  
man Server   18644 pages
apropos Keyword Search (all sections)
Output format
YellowDog logo
[printable version]

EXP2(P)			   POSIX Programmer's Manual		       EXP2(P)

NAME
       exp2, exp2f, exp2l - exponential base 2 functions

SYNOPSIS
       #include <math.h>

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

DESCRIPTION
       These functions shall compute the base-2 exponential of x.

       An  application	wishing to check for error situations should set errno
       to zero and  call  feclearexcept(FE_ALL_EXCEPT)	before	calling	 these
       functions.   On return, if errno is non-zero or fetestexcept(FE_INVALID
       | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error  has
       occurred.

RETURN VALUE
       Upon successful completion, these functions shall return 2**x.

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

       If the correct value would cause underflow, and is not representable, a
       range error may occur, and    either 0.0 (if supported), or   an imple‐
       mentation-defined value shall be returned.

       If x is NaN, a NaN shall be returned.

       If x is ±0, 1 shall be returned.

       If x is -Inf, +0 shall be returned.

       If x is +Inf, x shall be returned.

       If  the	correct	 value	would cause underflow, and is representable, a
       range error may occur and the correct value shall be returned.

ERRORS
       These functions shall fail if:

       Range Error
	      The result overflows.

       If the integer expression (math_errhandling & MATH_ERRNO) is  non-zero,
       then  errno  shall  be  set  to	[ERANGE].  If  the  integer expression
       (math_errhandling & MATH_ERREXCEPT)  is	non-zero,  then	 the  overflow
       floating-point exception shall be raised.

       These functions may fail if:

       Range Error
	      The result underflows.

       If  the integer expression (math_errhandling & MATH_ERRNO) is non-zero,
       then errno  shall  be  set  to  [ERANGE].  If  the  integer  expression
       (math_errhandling  &  MATH_ERREXCEPT)  is  non-zero, then the underflow
       floating-point exception shall be raised.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       For IEEE Std 754-1985 double, 1024 <= x	implies	 exp2(	x)  has	 over‐
       flowed. The value x < -1022 implies exp( x) has underflowed.

       On   error,   the   expressions	(math_errhandling  &  MATH_ERRNO)  and
       (math_errhandling & MATH_ERREXCEPT) are independent of each other,  but
       at least one of them must be non-zero.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       exp()  ,	 feclearexcept() , fetestexcept() , isnan() , log() , the Base
       Definitions volume of IEEE Std 1003.1-2001, Section 4.18, Treatment  of
       Error Conditions for Mathematical Functions, <math.h>

COPYRIGHT
       Portions	 of  this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       --  Portable  Operating	System	Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2003	by  the	 Institute  of
       Electrical  and	Electronics  Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE and
       The  Open Group Standard, the original IEEE and The Open Group Standard
       is the referee document. The original Standard can be  obtained	online
       at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group		     2003			       EXP2(P)
[top]

List of man pages available for YellowDog

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net