obs1 VAR1=A VAR2=1 obs2 VAR1=A VAR2=1 obs3 VAR1=B VAR2=2 obs4 VAR1=B VAR2=2 obs5 VAR1=B VAR2=2 obs6 VAR1=C VAR2=1 obs7 VAR1=C VAR2=1 obs8 VAR1=C VAR2=2 obs9 VAR1=D VAR2=1   The output would simply be a count of "3" Count 1 - obs1 and obs2 match on VAR1 as both have a value of A and also match on VAR2 with value of 1 Count 2 - obs3, obs4, obs5 match on VAR1=B, match on VAR2=2 Count 3 - obs6 and obs7 match on VAR1=C, VAR2=1  I don't care about obs8 since it didn't match VAR2 with obs6 I don't care about obs9 since it doens't match VAR1 with any ... View more

where var1=var1 of a different observation. that's what i'm trying to count in the data. ... View more

It would be a count, it wouldn't be a frequency of observations. A count of how many times there are matching VAR1s that also have the same VAR2   i'm sorry if I'm not explaining it clearly enough. ... View more

thanks but that doesn't do it.   I want to count (tally?) how many times VAR1 matches another observation, so where VAR1=VAR1 and also meets the other condition - where both observations have the same VAR2.   So the output would just be a count of 2 in the example. ... View more