.
My question is whether there is a clever way to identify the stubnames
for a -reshape-. Consider this example:
sysuse auto, clear
foreach j in 1 2 3 4 5 {
gen x_`j'=rep78+`j'
gen y_`j'=rep78-`j'
}
drop y_3
gen id=_n
keep id x_* y_*
/*
This data-set contains the following variables which I want to -reshape-:
x_1 x_2 x_3 x_4 x_5
y_1 y_2 y_4 y_5
I want to -reshape- by stubnames x_ and y_.
In my "real" data-set, I know that all variables I want to end up with
as stubnames contain an underscore (_). They all also do contain numbers
after the underscore, but there is no regular pattern there.
Now, I am generating a -macrolist- with unique stubnames, but this seems
like a detour to me, especially the loop:
*/
ds *_*
foreach v in `r(varlist)' {
local f `=regexr("`v'","[0-9]+","")'
local n `n' `f'
local n: list uniq n
}
di "*** `n' ****"
reshape long `n', i(id) j(foo)
Two questions:
1) Is there a better way to identify stubnames for a -reshape-?
2) Is there a more straightforward way to arrive at a unique macrolist
than the one I chose? In particular, something like the -regexr()-
function, but with the ability to remove all instances (not just the
first) of the regular expression. Something like -subinstr()-, but for
regular expressions.
Thank you!
Philipp
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