st: Re: -label define- and -replace- when a variable may be missing

["Joseph Coveney" <stajc2@gmail.com>]

Michael McCulloch wrote:

I am cleaning data for a survey, in which for one question, respondents were
asked where they got their training.
There are 9 possible answers for this question, but as I monitor survey data
coming in, some may have missing values.
The online survey instrument creates the variables as they are filled in:
	what_types_of_training_did___1
	what_types_of_training_did___2, and so on up to 
	what_types_of_training_did___9	

In order to create reports but not have my do-file stopped by a missing (not yet
defined) variable, how can I modify the following code?

	gen training=. 
	replace training=1 if what_types_of_training_did___1==1 
	replace training=2 if what_types_of_training_did___2==1 
	replace training=3 if what_types_of_training_did___3==1 

	lab def lab_train 	1 "Accredited US School" ///
					2 "Accredited School outside US" ///
					3 "Unaccredited US School", modify

--------------------------------------------------------------------------------

I'm not quite sure what you've got in your dataset(s), but couldn't you test 
for existence of a variable in each passage of a loop?  Something like 

generate byte training = 0
foreach var of varlist what_types_of_training_did___? {
    local index : subinstr local var "what_types_of_training_did___" ""
    // Alternative:  local index = substr("`var'", -1, 1)
    quietly replace training = `index' if `var' == 1
}
#delimit ;
label define TrainingTypes
  1 "Accredited US School"
  2 "Accredited School outside US"
  3 "Unaccredited US School"
  . . .
  9 "Hard Knocks";
#delimit cr
label values training TrainingTypes

Depending upon the structure of your dataset(s), you might be able to use
-reshape- and -rename-, skipping the loop.

Joseph Coveney

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