SAS Enterprise Miner: SMOTE sampling with categorical variables

[mmaccora]

Hi everybody,

Do you know a way to perform SMOTE sampling in SAS Enterprise Miner with categorical variables ?

I have found a SAS code doing this task:
http://support.sas.com/resources/papers/proceedings15/3282-2015.zip

The problem is that my data set contains categorical explanatory variables and the code is only adapted to numeric variables.

However, I know that categorical variables could be handled (https://www.jair.org/media/953/live-953-2037-jair.pdf) for example using the suited R package SMOTE.

If you have a code example in SAS to perform such task, I would really appreciate to see how it works.

Thank you so much for your help,
Marco

[DougWielenga · Accepted solution]

The code you found uses the MODECLUS procedure which (as you pointed out) is intended for numerical data.  It also has the problem of not being able to scale to the size of typical data mining data sets.   The Cluster node in SAS Enterprise Miner does allow for using categorical variables in creating a cluster solution and is capable of handling large scale data.  Therefore, you might consider creating clusters with the Cluster node and then sampling from the segments it produces as desired to achieve a similar effect.  

The challenge with including categorical variables in a cluster solution is that they are natural segmenting variables already -- having all their mass at a set of distinct points -- while the numerical variables are typically distributed across a much greater set of values which must then be grouped based on centroids.  The resulting clusters, however, typically do not break cleanly based on the categorical variable levels and might produce a result that is more difficult to explain.    

Hope this helps!

Doug

[MBRACH]

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@DougWielenga wrote:

The code you found uses the MODECLUS procedure which (as you pointed out) is intended for numerical data.  It also has the problem of not being able to scale to the size of typical data mining data sets.   The Cluster node in SAS Enterprise Miner does allow for using categorical variables in creating a cluster solution and is capable of handling large scale data.  Therefore, you might consider creating clusters with the Cluster node and then sampling from the segments it produces as desired to achieve a similar effect.  

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Hey Doug,

Could you explain in more details how can we use the output of the cluster node to include it into SMOTE SAS code? 

I think I don't understand the idea.

I found this article about the method that allows categorical variables but there is only pseudocode provided:
http://support.sas.com/resources/papers/proceedings15/3483-2015.pdf

Any ideas how it could be implemented using SAS code?