Hi all,   I have a big data set for conditional logistic regression where I want to split it into two sets: train and test.  Data format as follow: ID Y X 1 1 10 1 0 12 1 0 13 2 0 20 2 1 5 . . 10000 0 11 10000 0 8 10000 1 16 10000 0 14 What I want is randomly pick ID with a ratio say, 7:3 on 10000 ID for train:test, and obtaining all the rows with the same ID.   Menawhile, how can I compute the predicted probability after running proc logistic procedure with strata ID ?   Thank you for your kind assistant.   ... View more

I have imported a data set from excel and I want to calculate the difference between two columns, StdTime and FinTime.  The format in SAS data set looks like this: StdTime     FinTime 5:30.45      5:33.02 4:20.10      4:15.14 6:03.55      6:05.21 where the text above read as m:ss.millisec and the time should be less tha 10mins. I want to add a column to my existing data set for the time difference between these two columns for each row but it seems the time format is not readable by SAS.  Please kindly help and thank you for your attention. ... View more