No values in correlation matrix

[yael]

Hello

I created a correlation matrix via PROC CORR and found that the variable FF, which is dummy variable, has no values with 3 other variables (which are continous variables). I attached here the result as I got

Any clue why this is happened?

Thanks a lot!

[Rick_SAS · Accepted solution]

This would happen if your FF variable is constant. The formula for the Pearson correlation has a denominator that contains the variance of the two variables. A constant variable has variance=0, which makes the correlation coefficient undefined. For example:

data a;
set sashelp.class;
c = 1;    /* constant value */
run;

proc corr data=a;
run;