Math Functions
PHP Manual

log1p

(PHP 4 >= 4.0.7, PHP 5)

log1p — Returns log(1 + number), computed in a way that is accurate even when the value of number is close to zero

Description

float log1p ( float $number )
Warning

This function is EXPERIMENTAL. The behaviour of this function, the its name, and surrounding documentation may change without notice in a future release of PHP. This function should be used at your own risk.

log1p() returns log(1 + number ) computed in a way that is accurante even when the value of number is close to zero. log() might only return log(1) in this case due to lack of precision.

Note: This function is not implemented on Windows platforms.

Parameters

number

The argument to process

Return Values

log(1 + number )

See Also


Math Functions
PHP Manual