=over =item log EXPR X X X X X =item log Returns the natural logarithm (base I) of EXPR. If EXPR is omitted, returns the log of L|perlvar/$_>. To get the log of another base, use basic algebra: The base-N log of a number is equal to the natural log of that number divided by the natural log of N. For example: sub log10 { my $n = shift; return log($n)/log(10); } See also L|/exp EXPR> for the inverse operation. =back