Natural logarithm
Syntax
log ( float $arg [, float $base = M_E ] ) : float
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
The logarithm of arg to base, if given, or the natural logarithm.
Examples
1 · arg
<? $arg = 12.34; $return = log($arg); echo $return; ?>
2.5128460184772
2 · base
<? $arg = 12.34; $base = 2; $return = log($arg, $base); echo $return; ?>
3.6252704893747