Re: st: Replacing grouped string values with longest string value in the group

[Maarten buis <maartenbuis@yahoo.co.uk>]

--- On Thu, 19/8/10, McDermaid, Cameron wrote:
> I want to replace string values in a group to the longest
> string value from the same variable within the group.
> 
> I have a dataset with a number of symptoms that come from
> different hospitals. Because of differences in coding
> practices and errors, there can be differences in values
> (e.g. spelling).  I will not know how many symptom values
> will be present in a given data set and the symptom values
> are always strings. I've grouped the variables by soundex
> code and want to use the longest Symptom value to replace
> the shorter ones in the group. 
> 
> The intent is to write an ado file that anyone can run with
> minimum interfacing to generate frequencies of Symptoms
> after they've been processed as above.

No looping is necesary, the -by- prefix is very useful for
situations like these:

*----------------------- begin example ---------------------
drop _all
input str30 ptom              str4 slike  slength  slongest
"ALTEREDLEVELOFCONSCIOUSNESS" A436         27       1
"ALTERED CONSCIOUSNESS"       A436         20       0
"ALTERED CONSCIOUSNESS"       A436         20       0
"BLURREDVISION"               B463         13       1
"CONVULSIONS"                 C514         11       1
"DIZZY"                       D200         5        1
"DIZZINESS/VERTIGO"           D252         17       1
"DIZZY/VERTIGO"               D252         13       0
end

bys slike (slongest) : gen longest = ptom[_N]
list ptom longest
*---------------------- end example ------------------------
(For more on examples I sent to the Statalist see: 
http://www.maartenbuis.nl/example_faq )

Hope this helps,
Maarten

--------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany

http://www.maartenbuis.nl
--------------------------


      

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