(PHP 3, PHP 4, PHP 5)log -- Natural logarithm

Description

float log (float arg [, float base])

If the optional base parameter is specified,

log() returns log_base

arg, otherwise log()

returns the natural logarithm of arg.

Замечание:

The base parameter became available

with PHP 4.3.0.

As always you can calculate the logarithm in base b

of a number n, but using the mathematical identity:

log_b(n) = log(n)/log(b), where log is the

neperian (or natural) logarithm.