(PHP 4 >= 4.1.0, PHP 5)log1p -- Returns log(1 + number), computed in a way that is accurate even when the value of number is close to zero
This function is EXPERIMENTAL. The behaviour of this function, the name of this function, and anything else documented about this function may change without notice in a future release of PHP. Use this function 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.