I have 13 dummy variables that share a common name like so (haven't included all 13 for space reasons)
describe Q23*
Variable Storage Display Value
name type format label Variable label
Q23Agricultur~k str5 %9s Q23: Agriculture
Q23Miningandq~g str5 %9s Q23: Mining
Q23Trade str5 %9s Q23: Trade
Q23Teaching str5 %9s Q23: Teaching
Q23Healthrela~k str5 %9s Q23: Health related work
Q23Transport str5 %9s Q23: Transport
Q23Repairing str5 %9s Q23: Repairing
Q23Construction str5 %9s Q23: Construction
Q23Manufactur~g str5 %9s Q23: Manufacturing
Q23Domesticwo~e str5 %9s Q23: Domestic work
They're all dummy variables taking on TRUE/FALSE values so I want to encode them as categorical. Since they have similar names, I figured this would do the trick
foreach x of varlist Q23* {
forvalues i = 1/13{
encode `x', gen(sector`i')
}
}
Yet what it does is generate 13 sector variables with names from 1 to 13, but all corresponding to agriculture, and none for the remaining variables.
describe sector*
Variable Storage Display Value
name type format label Variable label
--------------------------------------------------------------------------------------------------
sector1 long %8.0g sector1 Q23: Agriculture and livestock
sector2 long %8.0g sector2 Q23: Agriculture and livestock
sector3 long %8.0g sector3 Q23: Agriculture and livestock
sector4 long %8.0g sector4 Q23: Agriculture and livestock
sector5 long %8.0g sector5 Q23: Agriculture and livestock
sector6 long %8.0g sector6 Q23: Agriculture and livestock
sector7 long %8.0g sector7 Q23: Agriculture and livestock
sector8 long %8.0g sector8 Q23: Agriculture and livestock
sector9 long %8.0g sector9 Q23: Agriculture and livestock
sector10 long %8.0g sector10 Q23: Agriculture and livestock
sector11 long %8.0g sector11 Q23: Agriculture and livestock
sector12 long %8.0g sector12 Q23: Agriculture and livestock
sector13 long %8.0g sector13 Q23: Agriculture and livestock
What am I doing wrong? Why is the loop not working?
Thanks!
CodePudding user response：
It's hard to verify what you're doing wrong here without a small snippet of your data as a reproducible example (as ThelceBear mentions in their comment), but two pointers:
The language 'encoding dummy variables into categorical variables' doesn't really make sense in this instance (or any that I can think of). Dummy variables are just a special case of a categorical variable where the number of categories = 2. And if you start with 2 categories in your variable I can't see how you'd convert that into more than 2 categories without some additional data. Nevertheless, this is more of a semantic point -- I think what you mean is that you want to encode your string variables into numeric variables (based on your use of
encode).You do not need the inner loop. Currently, your code is making the
sector*variables 1-13 on the first iteration of the outer loop and then replacing those variables on the next, and so on, until the outer loop completes. The following code may help you resolve this:
local i = 1
foreach x of varlist Q23* {
encode `x', gen(sector`i')
local i = `i' 1
}
CodePudding user response：
This is not a full answer but a fine answer has already been posted, and this extra material is too awkward to fit into a comment.
For string variables with values "TRUE" and "FALSE" there is a direct solution:
local i = 0
foreach v of var Q24* {
local i
gen sector`i' = `v' == "TRUE"
label var sector`i' "`: var label `v''"
}
If some value other than "FALSE" were possible, you would need to catch that too unless you were happy that it would map to 0.