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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*);

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>**.

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).

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.

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.

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)

- NAME
- SYNOPSIS
- DESCRIPTION
- RETURN VALUES
- ERRORS
- USAGE
- ATTRIBUTES
- SEE ALSO

This document was created by man2html, using the manual pages.

Time: 02:39:32 GMT, October 02, 2010