Hi Sean, Try the command: attr(s.out$qi, "names") to get a list of the names of the quantities of interest available from your particular sim() object. It will, depending on the specific model and setx() call, give you something like: [1] "ev1" "ev2" "pv1" "pv2" "fd" "rr" Then you can access each quantity of interest, either by name or position. For example, if you wanted the first differences, you could get them as: myFirstDifferences<-s.out$qi$ev2 You can also reference them by position, if needed. For example: or: or: [1] TRUE James. -- James Honaker, Senior Research Scientist //// Institute for Quantitative Social Science, Harvard University ________________________________ From: zelig-bounces(a)lists.gking.harvard.edu [zelig-bounces(a)lists.gking.harvard.edu] on behalf of Mike Dylan [seancacti101(a)gmail.com] Sent: Wednesday, October 30, 2013 5:22 PM To: Zelig(a)lists.gking.harvard.edu Subject: [zelig] need to extract the qi values hi, I need to extract qi values from s.out to bring the results to another app. When I do this s.out$qi, I get all null values. Any idea what might be wrong? Regards, Sean