Hello,   I have a dataset that includes the frequency that participants did 94 different activities in the past 30 days (1 frequency variable for each activity, each on a 0-4 scale) as well as an additional 94 variables indicating where each activity took place (1=indoors, 2=outdoors, 3=NA if the activity was not done). I would like to aggregate across this information so that I have an aggregate indicator of how often outdoor activities were done, incorporating both the number of outdoor activities as well as how often each of these was done.   I am a little rusty on use of arrays. I tried to create arrays for the 94 frequency and 94 activity variables; my ultimate goal is to calculate a SUM of all thearrays, sum across columns frequency variables for which the participant indicated the activity was typically done outdoors (so, a sum function but including only those activities where the corresponding where variable = 2).   This is what I have for code below, but based on the aggregate value coming out, I don't think it is working correctly. Any ideas? Thank you!   data bl; set go.bl; *Create an array of all the WHERE variables; array actwhere {94} Ac1WatchTVwhere Ac1WatchMovieHomewhere [etc... each of these is a variable that shows the frequency the participate did a given activity, e.g. the first one here where they typically watched TV 1=indoors, 2=outdoors, 3=NA; I'm not going to list out all 94 here because it makes this hard to read]  *Create an array of all the FREQ variables; array actfreq {94} Ac1WatchTVfreq Ac1WatchMovieHomefreq [etc... again listing all 94 of these variables, which indicate the frequency of each activity on the 0-4 scale]    do i = 1 to 94; if actwhere{i} = 2 then do; *Trying to isolate activities done outside here before summing; act_outdoor_freq=sum(of actfreq{i}); *Trying to create a new aggregate variable that is the sum of the frequencies of all those activities done outside; end; end; run; ... View more