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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.

close