Thanks for the explanation, but I still cannot fathom the logic of
this implementation. If I want to drop a single or all variables
begining with r, I shall use a wildcard like r*, no matter whether I
have only one variable beginning with r in the dataset or not. If I
want to drop the literatral "r", I shall be able to do so by
specifying -capture drop r-.
Anyway, the practical issue here is: Is there a way to stop Stata
from playing smart in this type of situation? Thanks.
Eddy
> this is because in this dataset, there is only one variable with
the name
> beginning from "r"
> so, when you type: capture drop r
> Stata refers the variable name, r, as the variable resid
> So, that variable is dropped after you specify -capture drop r-
>
>
>
>
> ----- Original Message -----
> From: "Eddy" <[email protected]>
> To: <[email protected]>
> Sent: Tuesday, October 21, 2003 4:15 PM
> Subject: st: problem with -capture drop-
>
>
>> Dear Statalisters,
>>
>> I encountered an odd behavior of -capture drop-, and would
appreciate
>> advice.
>>
>> I have a program in which a variable called "resid" was created
>> first, and another variable "r" was created later. Before creating
>> "r", I want to make sure that there is no existing variable
sharing
>> the same name. So I issue
>>
>> capture drop r
>>
>> to make sure there is no "r" before it is created. The problem is,
>> the above line also drops "resid" which I'd like to keep it there.
>> The symptom can be illustrated as the follows.
>>
>> ---------- example -------------------
>> . set obs 100
>> obs was 0, now 100
>>
>> . gen resid = 1
>>
>> .
>> . sum resid
>>
>> Variable | Obs Mean Std. Dev. Min
>> Max
>>
-------------+--------------------------------------------------------
>> resid | 100 1 0 1
>> 1
>>
>> .
>> . capture drop r
>>
>> .
>> . sum resid
>> no variables defined
>> r(111);
>>
>> -------- end of example -------
>>
>> This is true for both Stata 7, 7SE, and 8SE. My question: Is this
the
>> intended behavior? Is there anyway to tell Stata to drop only
those
>> literally specified? Thanks.
>>
>> Eddy
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