log - Perldoc Browser

functions / log

(source, CPAN)

You are viewing the version of this documentation from Perl blead. This is the main development branch of Perl. (git commit fc11c0aa8ec93daee28d55bf3808ed48dbc7d259)

#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.