# scalb(3m) [sunos man page]

```scalb(3M)						  Mathematical Library Functions						 scalb(3M)

NAME

SYNOPSIS
cc [ 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(5).

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 floating-point exception is
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	     |See below.		   |
+-----------------------------+-----------------------------+
|MT-Level		     |MT-Safe			   |
+-----------------------------+-----------------------------+

The scalb() function is Standard. The scalbf() and scalbl() functions are Stable.

feclearexcept(3M), fetestexcept(3M), ilogb(3M), ldexp(3M), logb(3M), math.h(3HEAD), matherr(3M), scalbln(3M), attributes(5), standards(5)

SunOS 5.10							    1 Nov 2003								 scalb(3M)```

## Check Out this Related Man Page

```SCALB(P)						     POSIX Programmer's Manual							  SCALB(P)

NAME

SYNOPSIS
#include <math.h>

double scalb(double x, double n);

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

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, the scalb() function shall return x*r**n.

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

If n is zero, x shall be returned.

If x is +-Inf and n is not -Inf, x shall be returned.

If x is +-0 and n is not +Inf, x shall be returned.

If x is +-0 and n is +Inf, a domain error shall occur, and either a NaN	(if  supported),  or  an  implementation-defined  value  shall	be
returned.

If  x  is  +-Inf  and  n  is -Inf, a domain error shall occur, and either a NaN (if supported), or an implementation-defined value shall be
returned.

If the result would cause an overflow, a range error shall occur and +-HUGE_VAL (according to the sign of 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.

If the correct value would cause underflow, and is not representable, a range error may occur, and 0.0 shall be returned.

ERRORS
The scalb() function shall fail if:

Domain Error
If x is zero and n is +Inf, or x is Inf and n is -Inf.

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

Range Error
The result would overflow.

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.

The scalb() function 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
Applications should use either scalbln(), scalblnf(), or scalblnl() in preference to this function.

IEEE Std 1003.1-2001  only  defines the behavior for the scalb() function when the n argument is an integer, a NaN, or Inf. The behavior of
other values for the n argument is unspecified.

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.