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| From | Kieran McCaul <kieran.mccaul@uwa.edu.au> |
| To | "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |
| Subject | st: RE: Same code, same machine, same data, different results |
| Date | Thu, 6 Sep 2012 09:34:57 +0800 |
... If you are merging files, then you must be using a -sort- command prior to each merge. Use the option -stable- with each of these and see if the problem persists. eg: sort var1 var2, stable -----Original Message----- From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Mattia Landoni Sent: Thursday, 6 September 2012 5:10 AM To: statalist@hsphsun2.harvard.edu Cc: Colleen Honigsberg Subject: st: Same code, same machine, same data, different results Dear statalisters, a friend of mine has a bizarre problem. She is running a regression as follows: xi: regress a b c i.d i.e and her output is different every time. Has anyone ever seen a behavior like this? Below are some details. Environment: - Stata 11 - Windows 32-bit Precise description: The do-file imports several files from .csv, then merges them, then runs the regression. If I run the do-file, I get certain results. If I issue the same regression command again, I get again the same results, as it should be. However, if I re-run the do-file from the beginning, I get slightly different results and the regression even reports a slightly different number of observations. (Say, 2663 vs. 2666). Every time all the data are taken afresh from the same static .csv sources. There is nothing random about the do-file, that I know. The xi: command generates about 200 i-variables and a few, maybe 10, are dropped because of collinearity. There are more than 2500 observations. I could post the do-file here, but it's big and messy. If anyone has any insight after reading the above description, I'd be very glad to hear it. Thanks, Mattia -- Mattia Landoni +1 217 4-A-QUANT (from US) +39 02 3206 21676 (from Italy) GMT -05:00 (US East) * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/