Subsetting Averages Based on IDs in multiple columns?
I need a JSL script to take averages from multiple columns of data and subset them into a separate data table. However I need the averages to be grouped by multiple categorical identifiers. For example, for the data table below I would need the averages of SubjectA Group X, and Subject A Group y, as separate lines as shown in the second example table. Something similar to this previous question. ...