PHP log() Function

The log() function returns the natural logarithm of a number, or the logarithm of number to base.

float log ( float $arg [, float $base = M_E ] )

If the optional base parameter is specified, log() returns logbase arg, otherwise log() returns the natural logarithm of arg.

Example -

ParameterDescription
argThe value to calculate the logarithm for
baseThe optional logarithmic base to use (defaults to 'e' and so to the natural logarithm).

Return Values

The logarithm of arg to base, if given, or the natural logarithm.