I am sorry but I don't understand, as the coding example i have provided gives you what you have described in a previous response(see below-response i am talking about). If it is not giving you the right results can you please clarify? Thanks so much.
For the data set aref1._1, I would like to retain the columns an1, col1, and treat whereas for aref1._2 I would like to retain columns an1, col2, and treat. For aref1._3 I would like to retain an1, col3, and treat. Hopefully this will sufficiently clarify what I want.
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