szalas
06-05-2004, 11:00 AM
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
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