[Python-Dev] Re: [Python-checkins] python/nondist/sandbox/spambayes GBayes.py,1.7,1.8
Thu, 22 Aug 2002 17:55:55 -0400
> P(S|X) = (100+100)/200 = 1/2
> P(S|Y) = (500+500)/500 = 1/2
> too by the same reasoning. P(not-S|X) and P(not-S|Y) are also 1/2 each.
> So far, there's nothing a reasonable person can argue with.
And note that only an unreasonable person would argue that (100+100)/200 =
1, so don't even think about it <wink>. Of course those should have been
P(S|X) = 100/(100+100) = 1/2
P(S|Y) = 500/(500+500) = 1/2
There are probably other glitches like that. Work out the example
yourself -- it's much easier to figure it out than to transcribe all the
tedious numbers into a msg.