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```SCALB(3)                  Linux Programmer's Manual                 SCALB(3)
```

## NAME         top

```       scalb,  scalbf,  scalbl  - multiply floating-point number by integral
```

## SYNOPSIS         top

```       #include <math.h>

double scalb(double x, double exp);
float scalbf(float x, float exp);
long double scalbl(long double x, long double exp);

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

scalb():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 ||
_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
scalbf(), scalbl():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600
```

## DESCRIPTION         top

```       These functions multiply their first argument x by FLT_RADIX
(probably 2) to the power of exp, that is:

The definition of FLT_RADIX can be obtained by including <float.h>.
```

## RETURN VALUE         top

```       On success, these functions return x * FLT_RADIX ** exp.

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

If x is positive infinity (negative infinity), and exp is not
negative infinity, positive infinity (negative infinity) is returned.

If x is +0 (-0), and exp is not positive infinity, +0 (-0) is
returned.

If x is zero, and exp is positive infinity, a domain error occurs,
and a NaN is returned.

If x is an infinity, and exp is negative infinity, a domain error
occurs, and a NaN is returned.

If the result overflows, a range error occurs, and the functions
return HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively, with a sign
the same as x.

If the result underflows, a range error occurs, and the functions
return zero, with a sign the same as x.
```

## ERRORS         top

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

The following errors can occur:

Domain error: x is 0, and exp is positive infinity, or x is positive
infinity and exp is negative infinity and the other argument is not a
NaN
An invalid floating-point exception (FE_INVALID) is raised.

Range error, overflow
An overflow floating-point exception (FE_OVERFLOW) is raised.

Range error, underflow
An underflow floating-point exception (FE_UNDERFLOW) is
raised.

These functions do not set errno.
```

## CONFORMING TO         top

```       scalb() is specified in POSIX.1-2001, but marked obsolescent.
POSIX.1-2008 removes the specification of scalb(), recommending the
use of scalbln(3), scalblnf(3), or scalblnl(3) instead.  The scalb()
function is from 4.3BSD.

scalbf() and scalbl() are unstandardized; scalbf() is nevertheless
present on several other systems
```

```       ldexp(3), scalbln(3)
```

## COLOPHON         top

```       This page is part of release 3.51 of the Linux man-pages project.  A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.

2013-03-23                         SCALB(3)
```