$chars2 = count_chars($string2);
// L1-norm of difference vector.
- $difference = array_sum( array_map( array(&$this, 'difference'), $chars1, $chars2 ) );
+ $difference = array_sum( array_map( array($this, 'difference'), $chars1, $chars2 ) );
// $string1 has zero length? Odd. Give huge penalty by not dividing.
if ( !$string1 )