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PROC MIXED: Same data, same code, different results

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Occasional Contributor
Posts: 5

PROC MIXED: Same data, same code, different results

My company does 100% QC on all results programming.  My QC programmer are coming up with different results from a proc mixed (using to get estimates to calcuate a Spearman-Brown Prophecy, but that doesn't matter).  We could not figure out why so eventially I sent him my data set with only the relevent variables and the exact code I used [attached].

1) When I run the code I get a note that "Estimated G matrix is not positive definite." (not good!) and my intercept estimate is zero (0).

2) Whe my colleague runs the EXACT SAME code on the EXACT SAME data, he gets no error and an intercept estimate of 618.93.

 

I have no idea why!?!?

I sent the code and data to two more colleagues.  To add to frustration, one got my result and the other got my QC person's result.

 

We all have the same version of SAS (9.4), the same patch, and the same OS (windows).

Why would we be getting different results?

Why would it not be merging on my machine?

 

Code:

proc mixed data = JMdatii;
class MEMBER_MEMBERID;
model d_stf_score =;
random Int / subject = MEMBER_MEMBERID;
run;

 

 Attached:

(I tried to attach the data set, but kept geting an error.  If I figure out how to do it then I will in an updated post)

 

 

Occasional Contributor
Posts: 5

Re: PROC MIXED: Same data, same code, different results

the data set:

MEMBER_MEMBERID = subject ID

d_stf_score = a score from 0-100 for each subject

Super User
Posts: 19,837

Re: PROC MIXED: Same data, same code, different results

Contact Tech support and include your data.

 

Without the data no one can really assist. 

 

I would double check the N of the data to make absolutely sure the same data is going in to each model. I assume each person is starting off from a SAS data set.

Super User
Posts: 11,343

Re: PROC MIXED: Same data, same code, different results

Different hardware? Different math coprocessors can yield different results though usually small. BUT statistics work generates lots of these and accumulated differences may show.

 

Running on 32bit vs 64bit systems?

 

Occasional Contributor
Posts: 5

Re: PROC MIXED: Same data, same code, different results

I did contast SAS support, but thought I'd check here to see if anyone else had any ideas or different perspectives until SAS got back to me.  Same N, same data set, and in the output the same 201 patients going into each model.  It's really confusing.

 

We're all running on 64 bit and with the same HP laptops.

Super User
Posts: 19,837

Re: PROC MIXED: Same data, same code, different results

Can you post the differing outputs?

To attach a dataset you can zip the file and upload it. Without data or results were throwing random guesses out. 

Occasional Contributor
Posts: 5

Re: PROC MIXED: Same data, same code, different results

I zipped the data (attached)

Attachment
Occasional Contributor
Posts: 5

Re: PROC MIXED: Same data, same code, different results

output of the two programmers

Attachment
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