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List: wekalist
Subject: [Wekalist] Question regarding RF weights
From: Nathaniel Smoker <ntjs2 () kent ! ac ! uk>
Date: 2020-11-18 15:04:41
Message-ID: DB7PR01MB5292A7BDCE8D22DA760230A2C3E10 () DB7PR01MB5292 ! eurprd01 ! prod ! exchangelabs ! com
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I=92m using the random forest classifier in Weka. When the algorithm select=
s the best feature for a tree node based on the class impurity measure, it =
calculates the information (entropy) of the class for each value of a categ=
orical feature, in my case I have only binary features. It then computes th=
e class impurity measure based on a weighted sum of those information value=
s, where the weight for each feature value is given by the relative frequen=
cy of that feature value in the dataset.
I want to modify the calculation of that weight for each feature value, but=
I cannot find the part of the code where that weight is calculated.
Can you please tell me which part of the code handles this?
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<p class="xxmsonormal" style="background:white"><span \
style="font-size:12.0pt;color:black">I’m using the random forest classifier in Weka. \
When the algorithm selects the best feature for a tree node based on the </span><span \
style="font-size:12.0pt;color:black">class impurity measure</span><span \
style="font-size:12.0pt;color:black">, it calculates the information (entropy) of the \
class for each value of a categorical feature, in my case I have only binary \
features. It then computes the </span><span \
style="font-size:12.0pt;color:black">class impurity measure</span><span \
style="font-size:12.0pt;color:black"> based on a weighted sum of those information \
values, where the weight for each feature value is given by the relative frequency \
of that feature value in the dataset.<o:p></o:p></span></p> <p class="xxmsonormal" \
style="background:white"><span style="font-size:12.0pt;color:black">I want to modify \
the calculation of that weight for each feature value, but I cannot find the part of \
the code where that weight is calculated.<o:p></o:p></span></p> <p \
class="xxmsonormal" style="background:white"><span \
style="font-size:12.0pt;color:black">Can you please tell me which part of the code \
handles this?<o:p></o:p></span></p> </div>
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