I don't know what you expect Stata to do with all the output that is
produced separately for each -by- group. For example, do you want
separate matrices b, beta, v for each group? I guess you do.
It is more likely perhaps that you want to loop over the groups,
something like this:
egen group = group(myvar)
su group, meanonly
forval i = 1/`r(max)' {
probit ... if group == `i'
wtpcikr ... if group == `i'
matrix b`i' = e(b)
matrix beta`i' = b`i'/-b`i'[1,1]
...
}
See also
FAQ . . . . . . . . . . Making foreach go through all values of a
variable
8/05 Is there a way to tell Stata to try all values of a
particular variable in a foreach statement without
specifying them?
http://www.stata.com/support/faqs/data/foreach.html
SJ-2-2 pr0005 . . . . . . Speaking Stata: How to face lists with
fortitude
Q2/02 SJ 2(2):202--222 (no
commands)
demonstrates the usefulness of for, foreach, forvalues, and
local macros for interactive (non programming) tasks
<http://www.stata-journal.com/article.html?article=pr0005>
Nick
[email protected]
Henrik Andersson
I need to run identical regressions for different subsamples of my data
set. I have one variable that defines the different subsamples and I
would like to use this variable together with the "by" command. My
problem is that my regressions contain several command.
My regressions, together with my "post estimation" commands, look like
probit yes lnbid lninc if bid<=income
wtpcikr lnbid lninc if bid<=income, mym(mean1) expo
matrix b=e(b)
matrix beta=b/-b[1,1]
matrix v=e(V)/(b[1,1]^2)
ereturn post beta v, noclear
ereturn display
scalar sigma=1/-b[1,1]
display sigma
Using my variable that defines the different subsamples, I would like to
run the string of commands above for each subsample. Is this possible
using the "by" command?
*
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