I have a table with three variables: patient, time, drug. Let us say there are two patients. First patient received drug A at time 1 followed by drug B at time 2. Second patient received drug B at time 1 followed by drug A at time 2. I want to accumulate a substring for the group variable, such that patient 1 belongs to group "AB" and patient 2  belong to group "BA". Any suggestions are welcome! data want; input patient time drug $ group $; datalines; 1 1 A AB 1 2 B AB 2 1 B BA 2 2 A BA ; run;   ... View more

Why is SAS doing this? It is obviously wrong: t = intck('min', date1, date2); date1 is 18feb2023 12:59 date2 is 18feb 2023 13:20 The interval should be 21 minutes, but I am getting -699 minutes.  I understand it is confused by the military time, but what is the explanation and how to work around this? Any thoughts are welcome! ... View more

Old macro ps from RAND corporation is trying to get SAS to play ping-pong with R. The macro is from a family called Twang, named after R package that gets propensity scores, hence the name ps. However, the variable names are illegal for SAS, for example, table.name is not a good variable name. I cannot even rename it, SAS complains. Workaround? I would like this code to work: proc sql noprint; select distinct table.name into :elements separated by " " from _baltab order by table.name desc; quit; Many thanks!     ... View more