how to use logarithms in perl

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

HI i have a questions about using log in perl. i got a formula of term weight which is weight (i , j) = log of (number of documents in collection dived no. of terms i occurs)

however, i do not know how to put that in perl program. can anyone teach me? thanks

$title =~ s/log/logarithms/ - dvergin 2003-02-07

Comment on how to use logarithms in perl

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Re: how to use log in perl by robartes (Priest) on Mar 07, 2003 at 06:36 UTC
From the documentation of log: `log EXPR log Returns the natural logarithm (base e) of EXPR. If EXPR is omitted, returns 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 exampl +e: sub log10 { my $n = shift; return log($n)/log(10); } See also "exp" for the inverse operation.` [download] Please check your documentation more thoroughly - this was only a `perldoc -f log` away. CU Robartes-	[reply] [d/l] [select]
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Re: how to use log in perl
by robartes (Priest) on Mar 07, 2003 at 06:36 UTC

log

log EXPR
       log     Returns the natural logarithm (base e) of EXPR.
               If EXPR is omitted, returns 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 exampl
+e:

                   sub log10 {
                       my $n = shift;
                       return log($n)/log(10);
                   }

               See also "exp" for the inverse operation.
[download]

perldoc -f log

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