log

Natural logarithm

Description

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

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

Parameters

arg: The value to calculate the logarithm for
base: The 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.

See Also

log10
exp
pow