http://www.perlmonks.org?node_id=1017287


in reply to Ln calculation

As a reply I will just copy a excerpt from the manual:

log EXPR

log

Returns the natural logarithm (base e) of EXPR. If EXPR is omitted, returns the log of $_ .

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 exp for the inverse operation.