I am trying to use the loc function to subset a matrix but it is not working how I would like it to. I have a column of data that can contain up to 10 characters and I want to subset based on whether or not a set of 2 characters is within that string. Example: Entire variable contents could be "YAPTGR" and I want to keep that observation if that variable contains "PT." I have tried just doing loc(Variable = 'PT') but that only keeps the observation if 'PT' is the only contents of the variable. Is this possible using the loc function or do I need to use something else within IML? Thanks for the help!