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Oracle Data Mining

From: szalas <gszalach_at_hotmail.com>
Date: Sat, 5 Jun 2004 21:00:37 +0200
Message-ID: <c9t58m$a76$1@julia.coi.pw.edu.pl>


Hi,
I have question about Oracle implementation of data mining algorithm - O-Cluster.
In the paper "O-Cluster: Scalable Clustering of Large High Dimensional Data Sets" is said that algorithm chooses the best cutting plan in the histogram using chi-square statistical test :
2*(observed - expected)^2/expected > 3.843 ,where
observed - histogram count of the valley expected - average of the histogram counts of the valley and the lower peak I have clustered example set of data.
I found out using Data Mining Browser where cutting planes go through and used above-mentioned equation to calculate value of chi-square and I've never got value above 3.843
Data Mining Browser shows that histogram counts are in the range <0,1> so how can it be possible to achieve value 3.843 using above-mentioned equation.
I would be grateful if someone explains me what is going on Thanks in advance
szalas Received on Sat Jun 05 2004 - 14:00:37 CDT

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