Hello perl-ai!

I've been playing with AI::Categorizer for a week or two now, and am 
having difficulties creating a collection object using the InMemory 
module.  I'm new to perl and oop and programming for that matter, but 
I've managed to get the functionality I'm looking for from 
AI::Categorizer using Collection::Files.  However, it would be very much 
more useful and efficient if I could create the collection from memory.  
It seems that the collection is created, and I can load it into a 
knowledgeset.  I can even train NaiveBayes on the knowledge set and 
categorize documents (although I'm not sure that it's doing so 
properly.).  It seems that it's not acknowledging all of the categories 
that are included in the collection's documents, it seems to only be 
recognizing one document's category set as the set for the collection.  
The main error I'm getting is when I try to generate a stats_table using:

my $mem_experiment = $l_mem-> categorize_collection( collection => 
$c_mem_test );
print $mem_experiment-> stats_table;

Can't take log of 0 at 
/usr/local/share/perl/5.8.4/Statistics/Contingency.pm line 183.

Can anyone tell me where I'm going wrong?  I very much appreciate help 
from anyone who has gotten this working.  And thanks to Ken for creating 
this great tool.

-Bill


---------code snippet--------
my %doc;
my %dochash;

my $cars = AI::Categorizer::Category-> by_name(name => "cars");
my $trucks = AI::Categorizer::Category-> by_name(name => "trucks");
my $baseball = AI::Categorizer::Category-> by_name(name => "baseball");
my $seattle = AI::Categorizer::Category-> by_name(name => "seattle");

push(my @seahawks_categories,$cars,$trucks);
push(my @seattle_categories,$seattle,$baseball);


$doc{name} = "Seahawks";
$doc{content} = "The Seahawks are a pretty good team. I enjoy watching 
them, and going to Seattle to see them";
$doc{categories} = \@seahawks_categories;
$dochash{SeahawksDocTitle} = \%doc;

$doc{name} = "Seattle";
$doc{content} = "I like to go to seattle and watch the mariners and stuff";
$doc{categories} = \@seattle_categories;
$dochash{SeattleDocTitle} = \%doc;


my $collection = new AI::Categorizer::Collection::InMemory(     data =>  
\%dochash);

return($collection);