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Re: [libann-users] Feature map is unbalanced
From: |
John Darrington |
Subject: |
Re: [libann-users] Feature map is unbalanced |
Date: |
Sat, 28 Jun 2003 19:40:54 +0800 |
User-agent: |
Mutt/1.3.28i |
On Sat, Jun 28, 2003 at 08:30:12AM +0200, Johnny Wezel wrote:
I'm getting an exception "Feature map is unbalanced" which I don't
understand.
This means that the training data has an unequal number of samples per
class, and would therefore bias the result. One gotcha is that if you
call
fm.addFeature("class1", featureA);
fm.addFeature("class1", featureB);
and featureA happens to be identical to featureB then in fact, class1
will get only one feature. This is a result of ann::FeatureMap being
derived from std::set. In future versions perhaps it'll derive from
std::multiset instead.
J'
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