[R] importing from Stata

[Thomas Lumley]

On Mon, 16 Jan 2006, Dimitri Joe wrote:

>
> (i) I get a big R file (for example, a 15Mb Stata file became a 42Mb R
> file; after cleanup.import() from the Hmisc package, it drooped to 35Mb,
> but that's still more than 2x the original Stata file) which, in turn, I
> suspect is due the fact that
>
> (ii) factors are created using Stata labels as levels.

Your suspicion is wrong.

A more likely explanation is that Stata uses single-precision floating 
point by default and can use 1-byte and 2-byte integers. R uses double 
precision floating point and four-byte integers.


> I wonder if
>
> (i) there isn't a way of forcing each variable to be numeric or integer,
> maintaining it's original values (instead of "Stata labels" as "R
> levels"). Or,

Yes. If you read the help page for read.dta() it tells you how.

 	-thomas

Thomas Lumley			Assoc. Professor, Biostatistics
tlumley at u.washington.edu	University of Washington, Seattle