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From | Nick Cox <njcoxstata@gmail.com> |
To | "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |
Subject | Re: st: Macro Producing Different Results Each Time Executed |
Date | Thu, 22 Aug 2013 21:57:32 +0100 |
Yes. The results of -sort- can vary slightly. The point is that -sort foo- with (say) values of -foo- 1 2 2 3 3 3 4 can have several different solutions, all correct so far as the instruction is concerned, but different so far as other variables are concerned. -sort, stable- should ensure the same results. See also e.g. http://www.stata.com/support/faqs/programming/sorting-on-categorical-variables/index.html Nick njcoxstata@gmail.com On 22 August 2013 21:21, William Sankey <wsankey@gmail.com> wrote: > Dear Statalist, > > The following 'foreach' statement produces different results each time > it executes. My suspicion is that the sort does not necessarily happen > in the same order each time the program runs, hence what is dropped > and what is kept in the merge becomes different each time. > > Can the sort execute differently each time it is run, do you have > other thoughts on why I might be obtaining different results each time > this function is executed? > > Thanks in advance, > > foreach file in col1 col2 col4 col5 { > > use `file' , clear > > sort PRVDR_NUM > by PRVDR_NUM: gen keeper = 1 if _n==1 > keep if keeper==1 > drop keeper > > sort PRVDR_NUM > save myusing3, replace > > use mycostreports, clear > > by PRVDR_NUM: generate unique=1 if _N==1 | (_N==2 & psych_type=="Hosp") > keep if unique==1 > drop unique > > sort PRVDR_NUM > merge PRVDR_NUM using myusing3 > tab _merge > drop if _merge==1 > drop _merge > > *Tables: > > egen paytotal = total(ProviderPayments) if REG_G==9 > egen paytotal_b = total(ProviderPay_base) if REG_G==9 > gen change53 = (paytotal-paytotal_b)/paytotal_b if REG_G==9 > drop paytotal* > > *Executed for other changes* > > sum change1 - change53 > } > > -- > William J. Sankey > Johns Hopkins University > MA Public Policy '12 > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/faqs/resources/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/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/