I apologize in advance if this question is silly, but how do I create a mean variable by groups. Take the below table for example, I want to calculate a Var2 such that for the first 3 observations, Var2 is the mean(Var1 of the first 3 obs), and Var2 for the next 7 obs is mean(Var1 from id=4 to id=10). ie, to get from Table 1 to Table 2. Thank you! Table 1 ID Group Var1 1 A 1 2 A 1 3 A 4 4 B 3 5 B 3 6 B 3 7 B 3 8 B 3 9 B 3 10 B 10 Table 2 ID Group Var1 Var2 1 A 1 2 2 A 1 2 3 A 4 2 4 B 3 4 5 B 3 4 6 B 3 4 7 B 3 4 8 B 3 4 9 B 3 4 10 B 10 4 ... View more

Considering the following 7 tables, I currently have test.set1, and test.port199001 to test.port199005 (199001 simply refers to all the data from January of 1990, etc). I want to arrive at test.set2. So strictly speaking, I want to fill Var2 of test.set1 with the values from each of the individual test.portXXXXXX based the matching ID and date. How would I be able to do that?? Thank you very much in advance for helping me out! test.set1 ID Date Var1 Var2 1 199001 0.424477 . 2 199002 0.919131 . 3 199003 0.188546 . 4 199004 0.294916 . 5 199005 0.589303 . test.port199001 ID Var2 1 0.60478 2 0.696379 3 0.890347 4 0.281266 5 0.682892 test.port199002 ID Var2 1 0.1342 2 0.112347 3 0.129106 4 0.354384 5 0.290145 test.port199003 ID Var2 1 0.776273 2 0.156324 3 0.981456 4 0.006446 5 0.98249 test.port199004 ID Var2 1 0.524929 2 0.037742 3 0.633113 4 0.548542 5 0.324782 test.port199005 ID Var2 1 0.591753 2 0.507835 3 0.078124 4 0.244329 5 0.230047 test.set2 ID Date Var1 Var2 1 199001 0.424477 0.60478 2 199002 0.919131 0.112347 3 199003 0.188546 0.981456 4 199004 0.294916 0.548542 5 199005 0.589303 0.230047 ... View more

I have a dataset which goes from 1990 to 2010; and for each year, there are few hundred observations. And I am trying to "partition" the dataset into different tables by year. I have the following, but I am pretty sure I can't do it, so what is the correct way to do it? data work.test2; do y=1989 to 2010;           set work.test;           if year(date)=y; end; run; Thank you very much! ... View more