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scalb(3m)

Mathematical Library Functions                                       scalb(3M)



NAME
       scalb,  scalbf, scalbl - load exponent of a radix-independent floating-
       point number

SYNOPSIS
       c99 [ flag... ] file... -lm [ library... ]
       #include <math.h>

       double scalb(double x, double n);


       float scalbf(float x, float n);


       long double scalbl(long double x, long double n);

DESCRIPTION
       These functions compute x * r^n, where r is the radix of the  machine's
       floating  point  arithmetic.  When  r  is  2,  scalb() is equivalent to
       ldexp(3M). The value of r is FLT_RADIX which is defined in <float.h>.

RETURN VALUES
       Upon successful completion, the scalb() function returns x * r^n.


       If x or n is NaN, a NaN is returned.


       If n is 0, x is returned.


       If x is ±Inf and n is not −Inf, x is returned.


       If x is ±0 and n is not +Inf, x is returned.


       If x is ±0 and n is +Inf, a domain error occurs and a NaN is returned.


       If x is ±Inf and n is  −Inf,  a  domain  error  occurs  and  a  NaN  is
       returned.


       If  the  result  would  cause  an  overflow,  a  range error occurs and
       ±HUGE_VAL (according to the sign of x) is returned.


       For exceptional cases, matherr(3M) tabulates the values to be  returned
       by scalb() as specified by SVID3 and XPG3. See standards(7).

ERRORS
       These functions will fail if:

       Domain Error    If x is 0 and n is +Inf, or x is Inf and n is −Inf.

                       If   the   integer   expression   (math_errhandling   &
                       MATH_ERREXCEPT) is non-zero, then the invalid floating-
                       point exception is raised.


       Range Error     The result would overflow.

                       If   the   integer   expression   (math_errhandling   &
                       MATH_ERREXCEPT) is non-zero, then the  overflow  float‐
                       ing-point exception is raised.


USAGE
       An  application  wanting to check for exceptions should call feclearex‐
       cept(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(7) for descriptions of the following attributes:


       tab() box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i)


       ATTRIBUTE TYPEATTRIBUTE VALUE _ Interface StabilityCommitted  _  Avail‐
       abilitysystem/library/math _ MT-LevelMT-Safe _ StandardFor scalb(), see
       standards(7).


SEE ALSO
       math.h(3HEAD),    feclearexcept(3M),    fetestexcept(3M),    ilogb(3M),
       ldexp(3M),  logb(3M),  matherr(3M),  scalbln(3M),  attributes(7), stan‐
       dards(7)



Solaris 11.4                     27 Sept 2016                        scalb(3M)
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