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


From   Richard Goldstein <richgold@ix.netcom.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: editing string variables to remove letters and keep only numbers
Date   Tue, 18 Jun 2013 12:03:39 -0400

looks to me like you are putting what should be on one line onto two
lines without the "///" continuation; note that in the code below, the
loop should only have two lines, each starting with "replace"

Rich

On 6/18/13 12:00 PM, Michael McCulloch wrote:
> Nick, as it's NOW written (with your correction included), I still receive an "invalid syntax" error.
> This is my first exercise in learning -forval-, so even after reviewing the -help- I'm not sure how to troubleshoot further.
> 
> forval i = 1/`lmax' {
>      replace numstr = numstr + substr(id, `i', 1) if
> inrange(real(substr(id, `i', 1)), 0, 9)
>      replace letterstr = letterstr + substr(id, `i', 1) if
> !inrange(real(substr(id, `i', 1)), 0, 9)
> }
> 
> 
> 
> 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 5:09 PM, Nick Cox wrote:
> 
>> Should be
>>
>> forval i = 1/`lmax' {
>>
>>
>> Nick
>> njcoxstata@gmail.com
>>
>>
>> On 18 June 2013 01:06, Michael McCulloch <mm@pinestreetfoundation.org> wrote:
>>> In implementing the example, I wrote, based on the variable "id":
>>>
>>> gen length = length(id)
>>> su length, meanonly
>>> local lmax = r(max)
>>> gen numstr = ""
>>> gen letterstr = ""
>>>
>>> forval i = 1/`max' {
>>>     replace numstr = numstr + substr(id, `i', 1) if
>>> inrange(real(substr(id, `i', 1)), 0, 9)
>>>     replace letterstr = letterstr + substr(id, `i', 1) if
>>> !inrange(real(substr(id, `i', 1)), 0, 9)
>>> }
>>>
>>> The forval statement is where I am getting the invalid syntax error.
>>>
>>>
>>> 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 5:02 PM, Nick Cox wrote:
>>>
>>>> Yes. The negation is intended. If a character isn't 0 to 9, it's
>>>> regarded as a a letter.
>>>>
>>>> Show us the exact code you typed to get a better answer.
>>>> Nick
>>>> njcoxstata@gmail.com
>>>>
>>>>
>>>> On 18 June 2013 00:51, Michael McCulloch <mm@pinestreetfoundation.org> wrote:
>>>>> 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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