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Re: st: Use varlabel in expressions
From
Nick Cox <[email protected]>
To
[email protected]
Subject
Re: st: Use varlabel in expressions
Date
Sat, 24 Mar 2012 08:08:14 +0000
Joerg and also Sven Trelle are naturally correct.
Note that -ds- (and also -findname- (SSC, SJ)) implement the loop
over variables for you.
With -ds-
ds, has(varl "na-") detail
drop `r(varlist)'
With -findname-
findname, varlabeltext(na-) detail
drop `r(varlist)'
A difference here over the approach below is that you get to see the
variables' details before you -drop- them.
Nick
On Fri, Mar 23, 2012 at 7:39 PM, Joerg Luedicke
<[email protected]> wrote:
> Perhaps consider the following example. It is assumed that "na-"
> is always "na-" exactly (e.g., not "na -" or "n a-") and that it will always
> affect the exact first 3 columns of the variable label. If these
> assumptions do not hold, something else may be needed,
> depending on the exact problem.
>
> *---------------------------
> sysuse auto, clear
> gen x=1
> label var x "na-whatever"
>
> foreach v of varlist _all {
> loc lab : variable label `v'
> if substr("`lab'", 1, 3)=="na-" {
> drop `v'
> }
> }
> *---------------------------
>
> J.
>
>
>
> On Fri, Mar 23, 2012 at 11:53 AM, Marcelo Lafleur <[email protected]> wrote:
>> I've had not luck with this and all references in this list point to use
>> of value labels.
>>
>> My question is simple: How, if possible, to drop variables based on a
>> prefix in their varlabels?
>>
>> Examples:
>>
>> . des mv218 mv225 mv245 mv246
>>
>> variable name value label variable label
>> ----------------------------------------------------------------------------
>> mv218 number of living children
>> mv225 mv225 na-current pregnancy wanted
>> mv245 women fathered children
>> with
>> mv246 mv246 na-married to mother when first
>> child was born
>>
>> (I edited the output a bit)
>>
>>
>> I want to drop mv225 and mv246 by testing that the variable label starts
>> with "na-"
>>
>> Having hundreds of variables in each dataset, it would be impractical to
>> do by hand.
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