Re: st: editing string variables to remove letters and keep only numbers

[Michael McCulloch <mm@pinestreetfoundation.org>]

Thanks Nick.

On the second inrange argument, does the "!" belong there?
When I run that forval command, an invalid syntax r(198) code is returned.



Best wishes,
Michael McCulloch, LAc MPH PhD

--
Pine Street Foundation, since 1989
124 Pine Street | San Anselmo | California | 94960-2674  
P: (415) 407-1357 | F: (206) 338-2391 | http://www.PineStreetFoundation.org

On Jun 17, 2013, at 4:10 PM, Nick Cox wrote:

> There are is a dedicated functions in -egenmore- (SSC) (-sieve()-)
> but let's take it from first principles.
> 
> gen length = length(strvar)
> su length, meanonly
> local lmax = r(max)
> 
> gen numstr = ""
> gen letterstr = ""
> 
> forval i = 1/`max' {
>      replace numstr = numstr + substr(strvar, `i', 1) if
> inrange(real(substr(strvar, `i', 1)), 0, 9)
>      replace letterstr = letterstr + substr(strvar, `i', 1) if
> !inrange(real(substr(strvar, `i', 1)), 0, 9)
> }
> Nick
> njcoxstata@gmail.com
> 
> 
> On 17 June 2013 23:53, Michael McCulloch <mm@pinestreetfoundation.org> wrote:
>> I have a variable in my dataset that (due to changes in data entry practices over time) contains several styles of the variable ID:
>> 
>>        - a number (e.g. 164)
>>        - a letter-number combination (e.g. e64)
>>        - a comma-separated letter-number combination (e.g. e64,e65)
>> 
>> In seeking to (A) remove the letters, and (B) separate the comma-separated into two separate variables, ID1 and ID2, I wrote the following argument:
>> 
>> . split ID, p(",")
>> . gen str id1_new =""           // make new ID to separate out the "e" from ID
>> . replace id1_new=substr(id1,2,3)
>> 
>> 
>> This successfully splits ID into ID1 and ID2.
>> 
>> This also works if:
>>        a 3-digit variable has a preceding letter (e64 is changed to 64)
>> 
>> However, in the case of a 3-digit values WITHOUT PRECEDING LETTER, the first digit is removed (164 is changed to 64).
>> 
>> Any suggestions would be appreciated.
>> 
>> 
>> Best wishes,
>> Michael McCulloch, LAc MPH PhD
>> 
>> --
>> Pine Street Foundation, since 1989
>> 124 Pine Street | San Anselmo | California | 94960-2674
>> P: (415) 407-1357 | F: (206) 338-2391 | http://www.PineStreetFoundation.org
>> 
>> 
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