Re: st: How to apply a command to numeric variables only

["paul o'brien" <paul.obrien@afe2.org.uk>]

Thanks NIck,

I encounter a problem with each of these suggestions:

With ds and findname I get: srhcareactivity4 not labeled

With -capture- inside the loop I get: variable string not found

On keeping the label I get: unrecognized command:      local invalid =
command name

Can you help?

Thanks for all your very useful advice on the List.

Paul


On 29/05/2012, Paul O'Brien <paul.obrien@afe2.org.uk> wrote:
> Thanks NIck,
>
> I encounter a problem with each of these suggestions:
>
> With ds and findname I get: srhcareactivity4 not labeled
>
> With -capture- inside the loop is get: variable string not found
>
> On keeping the label I get: unrecognized command:      local invalid command
> name
>
> Is there a tweak we are missing?
>
> Paul
>
> On 29 May 2012, at 08:27, Nick Cox wrote:
>
>> Similar questions arise often on this list. In your case one solution
>> is to -destring- the string variables before the loop, but then the
>> loop will convert back, so that does not appeal.
>>
>> Another is to select numeric variables beforehand. -ds- will do this
>>
>> ds srhcareactivity1-srhcareactivity6 , has(type numeric)
>>
>> foreach var in `r(varlist)' {
>>
>> -findname- (SJ) can do more than -ds- (fact) and has a better syntax
>> (opinion), but its use is very similar here.
>>
>> findname srhcareactivity1-srhcareactivity6 , type(numeric)
>>
>> foreach var in `r(varlist)' {
>>
>> Another way is to use -capture- inside the loop.
>>
>> foreach var of varlist srhcareactivity1-srhcareactivity6{
>>     capture decode `var', generate(string)
>>     if _rc == 0 {
>>             drop `var'
>>             rename string `var'
>>      }
>> }
>>
>> Is it "string" a reserved word? (I am away from manuals at the
>> moment.) I'd use something different here, even if not.
>>
>> Keeping the variable label can be done with extended macro functions,
>> mentioned frequently on this list.
>>
>> foreach var of varlist srhcareactivity1-srhcareactivity6{
>>     local varlabel : variable label `var'
>>     capture decode `var', generate(string)
>>     if _rc == 0 {
>>             drop `var'
>>             rename string `var'
>>             label var `var `varlabel'
>>      }
>> }
>>
>> See -help extended fcn-. Or -help macro- first.
>>
>> Nick
>>
>> On Tue, May 29, 2012 at 6:28 AM, Paul O'Brien <paul.obrien@afe2.org.uk>
>> wrote:
>>> I want to do a foreach command to convert numeric variables to string
>>> before a merge. Only some of the variables are numeric and which ones
>>> varies with each database.
>>>
>>> foreach var of varlist srhcareactivity1-srhcareactivity6{
>>>        decode `var', generate(string)
>>>        drop `var'
>>>        rename string `var'
>>> }
>>>
>>> Error message: not possible with string variable.
>>>
>>> I have tried using capture to ignore the error.
>>>
>>> How can I restrict the command to numeric variables only?
>>>
>>> By the way, is there a way to keep the variable label which is lost when
>>> I use generate.
>>>
>>
>> *
>> *   For searches and help try:
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>> *   http://www.ats.ucla.edu/stat/stata/
>
> -------------------------------
> Dr Paul O'Brien
> Raymede Clinic
> Westside Contraception and Sexual Health Services
> Central London Community Healthcare
> Exmoor St
> London
> W10 6DZ
> UK
> +44 (0)20 8962 4450
>
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*
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