Re: st: Re: Request code simplification

[Rebecca Pope <rebecca.a.pope@gmail.com>]

Sorry, just saw the correction & answers posted by others.
http://www.stata.com/statalist/archive/2013-06/msg00499.html

-Rebecca

On Wed, Jun 12, 2013 at 9:26 AM, Rebecca Pope <rebecca.a.pope@gmail.com> wrote:
> Mike,
> First things first, a point of order: -carryforward- is a user-written
> command and you are asked to please identify these when you use them
> and note from where you have obtained them.
>
> Second, I tested your (slightly modified) code on my computer using a
> test set built off of what you posted with a total of 270,000
> observations (you just said "thousands", so I made it of moderate
> size). Total run time was 0.79 seconds. So, if you are having computer
> problems, my suggestion would be to check what else is running on your
> computer.
>
> Finally, this may be a stupid question, but if you are trying to find
> patients with transplants, why aren't you searching for type_of_visit
> = (code for transplant). Does the other stuff you posted serve some
> greater purpose you didn't mention?
>
> There are multiple ways of handling the code for searching for
> transplants. The easiest, I think, would simply be:
>
> *** begin example ***
> gen transplant = -1*strmatch(type_of_visit,"*transplant")
> bys pat_id (transplant): gen countthis = (-1*transplant) if _n==1
>
> tab countthis
> *** end example ***
>
> The code above ran in 0.22 seconds. Timing is from a machine with 4 GB
> of RAM and an Intel Core i5-2400 3.1 GHz processor. Performance on
> your laptop will likely differ, but I see no reason why either
> approach would cause a crash.
>
> Regards,
> Rebecca
>
> On Tue, Jun 11, 2013 at 4:14 PM, Michael Stewart
> <michaelstewartresearch@gmail.com> wrote:
>> Hello,
>>
>> I am  working on a data set with thousands of patients( and multiple
>> records per patient) and I am trying to identify pateints with any
>> transplant(could undergo liver, kidney, intestine etc) . I was
>> wondering if we could simplify my  code as my laptop is freezing with
>> the following set of commands.
>>
>>
>> Here the goal is find patients who has
>> type_of_visit[1]=="first_clinic_visit" & any other type_of_visit is
>> "".(after the records are sorted by pat_id and visit_date)
>>
>> My code :
>>
>> bysort PAT_ID (visit_date):carryforward VISIT,gen(v)
>> bysort PAT_ID (visit_date):gen x=v[1]==v[_n]
>> bysort PAT_ID (visit_date):egen z=sum(x)
>> bysort PAT_ID (visit_date):egen zz=count(x)
>> gen y= z< zz
>>
>>
>> The dataset format is as follows.
>>
>> pat-id     visit_date     type_of_visit
>> -------------------------------------------------------
>> xxx      09/01/2003      first_clinic_visit
>> xxx      09/15/2003
>>                 .
>>                 .
>>                 .
>>                 .
>> XXX      12/12/2003
>> XXX      2/04/2004       liver_transplant
>> yyy      01/01/2004      first_clinic_visit
>> yyy      02/02/2005
>>                  .
>>                   .
>> yyy     01/03/2008      intestine_transplant
>> zzz      05/01/2010     first_clinic_visit
>> zzz     05/03/2011
>>                   .
>>                   .
>>                   .
>>                   .
>> ------------------------------------------------------------
>>
>> As always, thanks a lot for your time
>> Thank you ,
>> Yours Sincerely,
>> Mike.
>> *
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