Thanks for pointing it out! Rescaling alone would not fix the issue, but when doing it along with removing the type= option does the job, but I'm sure why it works that way. ... View more

I tried type=vc, but it didn't work. Then I removed the type= option and it worked (along with rescaling both views and ola). Thanks a lot for your advice! What does it mean when I remove the type= option completely, and when type= vc? What does it mean to change the convergence criterion to stopgap? What is the syntax to do so, or to change the convergence criterion to a larger number?   Thanks again! ... View more

Thanks for your reply. I did try removing all rows when OLA=0, and rescale Views and OLA. However, it still did not converge.    data MIXED_DATA; set MIXED_DATA; if OLA ne 0; views10=views/10000000; ola10=ola/1000000; run;   proc mixed data=MIXED_DATA ITDETAILS LOGNOTE; class Top_IND; model Views10= ola10 / ddfm=kr2 solution; random int ola/ subject=Top_IND type=un g solution; run;   ... View more

Thanks a lot for your reply. I did give your code a shot and it returned an error message "Only CLASS variables allowed in this effect."Only CLASS variables allowed in this effect." Please see the screenshot.  I also tried the noint option, and it didn't work (not sure if I'm having the right code). I'm wondering what are CovP1 CovP2 CovP3 CovP4 in the Iteration History.    proc mixed data=MIXED_DATA ITDETAILS LOGNOTE; class Top_IND; model Views= ola / ddfm=kr2 noint solution; random int ola/ subject=Top_IND type=un g solution; run;   Views are the number of website visits, and OLA, Twitter, Home_based are all continuous variables contributing to views. I do think their respective coefficients will be different when top_ind=1 vs when top_ind=0. So if proc mixed is not the appropriate approach, what approach do you think would be more appropriate? must I run two separate regression models?   Thanks again for your help! ... View more

Thanks for your quick reply! Those cells are indeed 0's. Basically, I have the time-series data, and views are supported by different channels, and OLA is one of them. It is 0 when it is off. I did give it a try to run the procedure only OLA is not 0, but it also did not converge.   ... View more