topic Proc mixed and integer overflow in Statistical Procedures

Proc mixed and integer overflow

miminz85 — Mon, 05 Dec 2016 01:02:38 GMT

Hi there

I have found several posts on this subject but have not managed to solve my problem yet.

I am running a mixed model on a dataset with 30 subjects who have got an average of 4000 measurements each (The highest number of measurements per subject is 16000).

I have run the model using the RANDOM statement (with a random intercept for each subject) and it worked fine.

However, I would like to change the covariance structure to an autogressive one. For this reason I have been trying to use the REPEATED statement and I keep getting the following error

ERROR: Integer overflow on computing amount of memory required. A request to allocate 5952.94M bytes of memory can not be honored.
ERROR: The SAS System stopped processing this step because of insufficient memory.

I tried to make the model the simplest possible (without any fixed effect) and I have tried to change the DDFM option but it still doesn't work.

Does anyone know how to fix it?

Thanks a lot!!!

Re: Proc mixed and integer overflow

Rick_SAS — Mon, 05 Dec 2016 13:29:45 GMT

You could try PROC HPMIXED, which uses sparse matrices to compute the model. See the paper "All the cows in Canada..." (Wang and Tobias, 2009)

Re: Proc mixed and integer overflow

miminz85 — Mon, 05 Dec 2016 23:31:30 GMT

Hi Rick!

Thanks for this. I tried but I still get the following message :(:

ERROR: The HPMIXED procedure stopped because of the insufficient memory.

This is my code. I got rid of the fixed effects so that it would be the simplest possible.

proc hpmixed data=j; 
    class seconds;
    model logconcentration=; 
    repeated seconds/sub=worker_id type=AR(1); 
run;

Re: Proc mixed and integer overflow

Rick_SAS — Tue, 06 Dec 2016 12:48:21 GMT

I assume you are using the MEMSIZE system option to make sure the SAS process has access to as much RAM as possible?

Re: Proc mixed and integer overflow

miminz85 — Tue, 06 Dec 2016 21:33:17 GMT

Thanks Rick. I have just done it but my computer has got a 4GB RAM and it is not enough ...