Hi
I am calculating multiple Correlations for long lists of data. I want the correlation based on the value in a given column. In the below example I would like a different correlation for each value in colA and the correlation will be between colC and colD. ColB lists the different people whose data are used for the correlations. In actuality there are 30 or more people for each test. In every case ColC is the same for a given value of ColB (although I doubt that matters). The number of people taking each test varies. I would like a correlation of ColC an ColD for each value of ColA.
Thanks!

Simplified version of my data

ColA ColB ColC ColD
Test1 Fred .75 1
Test1 Max .80 0
Test1 Sara .90 1
Test2 Fred .75 1
Test2 Max .80 1
Test2 Sara .90 0
....
Test100 Fred .75 1
Test100 Max .80 1
Test100 Sara .90 1