Monday, March 20, 2006
RE: st: looping
bysort state county age race : egen totalmales = total(males * perwt) by state county age race : egen totalfemales = total(females * perwt) gen ratio = totalmales / totalfemales
Scott Cunningham > On Mar 20, 2006, at 9:42 AM, n j cox wrote: > > > You should read some basic accounts of -by:-. > > > > Also, please note the advice in the Statalist FAQ: > > > > "Statalist is an international list. Please explain details that > > may make sense only in your own corner of the world." > > > > Some of the details here presuppose knowledge of your local > > situation, which I guess to be the United States. It is > likely that > > many members of Statalist do not know what "msa" means, for example. > > > > I am still in the dark on what an observation in your dataset > > looks like, or what it represents. I assume that -males- and - > > females- are numeric variables, but are they dummies or do they > > include > > counts? In either case, what is -perwt- precisely? > > Sorry about the ambiguity. I did forget my audience. I am working > with a special sample from the 2000 United States Census called the > longform. It is a sample of households - I think > approximately 5% of > the US population received the survey. An observation is a > household, but since only 5% of all households were sampled, > you must > use the person weights (-perwt-) when working with this data. So, > for instance, if a certain household is sampled and they represent 5 > households, then the perwt=5. Males and females are numeric values. > > > > > Either way, I guess that -egen, total()- with heavy use of -by()- > > or -by:- is the easiest way to get totals of males and females, > > after which you get ratios directly. It should take about 3 lines > > of Stata. The only looping would be that tacit in -egen-. > > I've been using egen to sum males and females, but was unsure of how > to implement the looping over all US county variables. This > is where > -by county- wouuld come in, correct?
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