Ernest Berkhout
> i was looking for a way to cycle through all the values of a
> particular
> variable 'oplnr' without having to hardcode these values (they changes
> every year). Walking through some faqs I come across the
> program 'vallist'
> which should be able to do this for me. I integrated this in a small
-vallist- is considered by its author to have been superseded by -levels-
(also same author). type -ssc desc levels-.
> foreach-loop program, but I get an errormessage that does not
> make sense to
> me. As I'm not very experienced in programming Stata, it might be some
> silly typo which I overlooked, but I cant see what is is. Or
> is there maybe
> some other problem unknown to me?
>
> (snip)
>
> The following is the code that I've written:
> ******************************
> gen temp=.
> vallist oplnr
> foreach oplnr of local r(list) {
> forvalues brinnr = 1/13 {
> gen byte opXbr_`oplnr'_`brinnr' = (oplnr==`oplnr' &
> brinkort==`brinnr')
> qui summ opXbr_`oplnr'_`brinnr', meanonly
> replace temp=r(max)
> if temp==0 drop opXbr_`oplnr'_`brinnr'
> }
> }
> drop temp
> ********************************************
>
> The error message I get is:
>
> { required
> r(100)
r(list) is a special kind macro, one that is saved in the r-space which is a
namespace common to rclass programs. The macros in r(), (or e() and s() for
that matter) are not really local macros, e.g.
use c:\stata\auto
vallist foreign
* show the contents of r(list)
* i.e it expands _like_ a local macro with the single-quotes
di "`r(list)'"
* but doesn't turn up when we list the contents of local and global macros
macro dir
* it does show up when we list the contents of the r-space
return list
In your loop, replace the line
foreach oplnr of local r(list)
by
foreach oplnr in `r(list)'
or by the following two lines
local myrlist = r(list)
foreach oplnr of local myrlist
which in effect copy the rclass macro r(list) into a (truly) local macro
Patrick Joly
[email protected]
[email protected]
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