RE: st: egen with user-defined function

[Jan Barendregt <j.barendregt@sph.uq.edu.au>]

Hi Nick,

Thanks for your reply. This is what I'm trying to do. I'm looking at multiple cause of death data, trying to find the number of cases where sepsis has been mentioned on the death certificate. Each death can have from 1 up to 20 different codes. In the dataset, these codes are in a single string in the RECORD_AXIS_DATA field, with the RECORD_AXIS_COUNT field giving the number of codes for this record. So I'm parsing the string, search for any of the codes that are used for sepsis, and generate a new field that contains 0 of none is found, and 1 or more otherwise.
I'm not a regular Stata user, so you may well be right that there are easier ways of doing this.

Thanks,

Jan

------------------------------------------
Jan J Barendregt, MA, PhD
Assoc Prof of Epidemiological Modelling
School of Population Health, University of Queensland
Email: j.barendregt@sph.uq.edu.au
Skype: janbarendregt
Phone: +61 7 3102 3093
Visit www.epigear.com: home of Ersatz, MetaXL, DisMod II, Prevent, and more! 

> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu 
> [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Nick Cox
> Sent: Tuesday, 20 August 2013 10:41 AM
> To: statalist@hsphsun2.harvard.edu
> Subject: Re: st: egen with user-defined function
> 
> I don't see quite what -egen- is objecting to here but you have more
> fundamental problems.
> 
> Wiring in particular names to a program is not illegal but it usually
> implies that you are pitching your problem at the wrong level.
> 
> (*) I guess that you have some variable -RECORD_AXIS_DATA- and you are
> looking for occurrences of the strings "A410" ... "A419".
> 
> Your code would at most look in the first observation as you are using
> the -if- command
> instead of an -if- qualifier.
> 
> It would be probably be best if you described the concrete problem, as
> my strong guess is that no original program is needed here.
> 
> But I'll guess that (*) is the nub of the problem.
> 
> clonevar copy = RECORD_AXIS_DATA
> 
> qui forval i = 0/9 {
>       replace copy = subinstr(copy, "A41`i'", "", .)
> }
> 
> gen count = (length(RECORD_AXIS_DATA) - length(copy)) / 4
> 
> So in a copy of the variable we replace each occurrence of "A410"
> "A411" ... "A419" with an empty string. Each such deletion reduces the
> number of characters by 4.
> 
> This was written up in 
> http://www.stata-journal.com/article.html?article=dm0056
> 
> 
> Nick
> njcoxstata@gmail.com
> 
> 
> On 20 August 2013 01:03, Jan Barendregt 
> <j.barendregt@sph.uq.edu.au> wrote:
> 
> > I'm trying to let egen to use a user-defined function. Here 
> is what I'm doing:
> >
> > do "C:\Ddrive\MattCooper\Data\test.do"
> >
> > . capture program drop _grecordparse
> >
> > . program define _grecordparse
> >   1. local bool=0
> >   2. local li=1
> >   3. local i=0
> >   4.   while `i' < RECORD_AXIS_COUNT {
> >   5.   if (substr(RECORD_AXIS_DATA,`li',4)>="A410") & 
> (substr(RECORD_AXIS_DATA,`li',4)<="A419") local bool=
> >> `bool'+1
> >   6.   local li=`li'+4
> >   7.   local i=`i'+1
> >   8.   }
> >   9.   gen `typlist' `varlist' = `bool'
> >  10. end
> >
> > .
> > end of do-file
> >
> > . egen sepsis=recordparse
> > unknown egen function recordparse()
> > r(133);
> >
> >
> > So I can't get egen to recognise my recordparse function. Any ideas?
> >
> > I'm using Stata 11.2 on Windows
> >
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