Can computer's performance affect Stata's output?

[Jean Jacques]

Hi Statausers

I feel it's a strange question, but I need to ask: I was running a Finite Mixture Model some months ago and the model was converging after some iterations and now that I run again the same do file, it keeps iterating without converging. The only difference is that my computer in this last two months has became slower. But still, my model before was converging after a few iterations and now after hundreds of iterations, still doesn't converge. Is it possible to explain this non-convergence by my computer's performance or it has to be a human error on my side and the same do file, should always work in the same way regardless the laptop?

Thanks a lot!

[Clyde Schechter]

Performance issues should not affect this.

The same do-file should always produce the same results with the same data. You should carefully check whether either the do-file or the data have somehow changed since you last ran this. It's also possible that you have applied updates to Stata in the interim, and that may have introduced a problem that did not previously exist.

The only thing I can think of that would, indirectly, relate performance to the problems you are having is if the performance slowdown is due to a failing hard drive, and that, in turn, is causing the computer to misread the data file. But even this seems unlikely, because the kind of random read errors that a failing hard drive would produce that would still get through the operating system's error-checking code are more likely to result in an invalid data set that Stata rejects than a corrupted file that otherwise looks normal and then analyzes badly.

[Jean Jacques]

Thanks Clyde, indeed it makes sense to assume an human error. However as I was sure about my do-file and in many "relatively simple" finite mixture models I wasn't having convergence, I wanted to check. I'll go back to my do file and see what can be wrong.

Thanks again!
Cheers