Convert Random Effects Covariance to a correlation

[Sanscrit_2prov]

Proc mixed allows you to output the random effects covariance matrix using an ods table statement. Would anyone know how to convert the covariances to correlations? 

[jiltao]

You can use the VCORR option in the RANDOM statement to get the correlation matrix for V, or the RCORR option in the REPEATED statement to get the correlation matrix for R.

[Sanscrit_2prov]

I have used the vcorr option but I want the correlation across the whole sample, not within each person. So it would be one correlation coefficient converted from the random effect covariance across all subjects.

[jiltao]

The correlation is generally the same from subject to subject. What is your PROC MIXED program?

[Ksharp]

Do you have SAS/IML?

Calling @Rick_SAS 

[Sanscrit_2prov]

Yes I have SAS IML

[Ksharp · Accepted solution]

Then check COV2CORR() function:

https://blogs.sas.com/content/iml/2012/02/17/convert-a-covariance-matrix-to-a-correlation-matrix-in-...

[Sanscrit_2prov]

Thank you very mch