From: Matthias Reitinger <reitinge+usenet@...>
Date: 2009-04-08T21:30:06+09:00
Subject: Re: what is happening here

George George wrote:
> i have some perl code
> 
> while ($high - $low > 0.001) {    # precision
>     # calculate the sum of all normalized scores
>     my $sum = Pn * Pn * exp($lambda * $match)    * 4
>             + Pn * Pn * exp($lambda * $mismatch) * 12;
> [...]
> trying to rewrite this in ruby
> while (high - low > 0.001)
>   #calculate the sum of all normalized scores
>   sum = Pn * Pn **(lambda * match) * 4 + Pn * Pn **(lambda * mismatch) *
> 12

It seems like you're using the ** operator wrong.  You should use Ruby's
Math.exp instead (which is the direct equivalent to Perl's exp).

-Matthias