Austin is right, it seems to me, although
I find the metaphor "knit your own" more
congenial.
The deeper issue is why StataCorp don't allow
this. It would need a very substantial change
to Stata's commands, as every command that
allows a varlist would have to be assessed
to see whether that could be changed to
what might be called a tvarlist, i.e.
a list of variable names and/or transformations
and variable names.
Then there is all the error checking and diagnostics,
e.g. what do you expect Stata to do if you ask for
list log(make) log(price) log(foreign)
In short, much more difficult than it sounds.
Nick
[email protected]
P.S. now StataCorp will make me look foolish by
announcing it's immiment.
Austin Nichols
> You could roll your own, by writing a wrapper for each regression
> command that parses expressions, generates tempvars, and labels them
> with the relevant expression. Don't users of R have to program their
> own stuff every time?
Feiveson, Alan H.
> > I have been demonstrating the wonders of Stata to
> users of R and
> > have been embarrassed by their criticism of Stata's inability to
> > transform a variable within the syntax of a command. For
> example reg y
> > log(x) won't work. The variable z=log(x) must be generated
> first. I'm
> > curious as to whether other statistical software besides R
> allows this
> > sort of thing. At any rate, I would strongly urge Stata Corp. to
> > incorporate this sort flexibility.
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