st: R and Stata efficiency

[David Airey <david.airey@Vanderbilt.Edu>]

I was talking to a statistician on our campus about his perception of  
the relative efficiency of R compared to Stata. One of the things he  
finds annoying about Stata is having to explicitly save things in  
addition to estimation:


> Examples are: in LR test, I need to save the results of a previous  
> model. In drawing graphs based on the model fit, I have to save the  
> coefficient matrix.  In doing further inferences on predicted  
> values, I have to save the predicted values. etc. etc.
>
> Stata commands seem to be designed to only take existant entities  
> as arguments, but cannot take the results of other functions as  
> arguments without explicit assignment.  In R, results of functions  
> can always be used as arguments for other functions, making  
> explicit assignment unnecessary if not needed.
Stata does leave behind model coefficients and such that can be  
directly accessed (without saving). But they disappear after the next  
estimation. Whereas in R, estimates are always saved in the way a  
command is issued (<-) and they remain accessible later, unless they  
are overwritten by mistake or intent later.

--
David C. Airey, Ph.D.
Research Assistant Professor

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