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st: RE: RE: RE: RE: RE: Using -collapse- extensively to find historical, irregular matches: Better way?


From   "Nick Cox" <n.j.cox@durham.ac.uk>
To   <statalist@hsphsun2.harvard.edu>
Subject   st: RE: RE: RE: RE: RE: Using -collapse- extensively to find historical, irregular matches: Better way?
Date   Tue, 30 Sep 2003 17:40:30 +0100

Should be _n - 1, not _N - 1. 

Nick 
n.j.cox@durham.ac.uk 

> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu
> [mailto:owner-statalist@hsphsun2.harvard.edu]On Behalf Of Nick Cox
> Sent: 30 September 2003 16:59
> To: statalist@hsphsun2.harvard.edu
> Subject: st: RE: RE: RE: RE: Using -collapse- extensively to find
> historical, irregular matches: Better way?
> 
> 
> Chih-Mao Hsieh
> > 	
> > 	I had been shying away from converting "cited" to 
> > strings because the numbers are in the millions, i.e. 
> > strings would be length 7.  Many of the "citing" patents 
> > have more than 35-40 "cited" patents, and so the 
> > concatenation might surpass the string's length limit.
> > 	
> > 	Of course, the chances are not high that two patents 
> > would match each other over the first 35 patents, so your 
> > way does appear to be better.
> 
> Another way is to -reshape-, something 
> like this: 
> 
> bysort citing (cited) : gen j = _n 
> reshape wide cited, i(citing) j(j) 
> bysort cited* (citing) : gen counter = _N - 1 
> 
> At this moment, I think that's a lot better
> than my earlier suggestions. 
> 
> Nick 
> n.j.cox@durham.ac.uk 
> 
> 
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