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Re: st: RE: Count presence of item on different vars


From   "Nikolaos A. Patsopoulos" <[email protected]>
To   [email protected]
Subject   Re: st: RE: Count presence of item on different vars
Date   Mon, 09 Oct 2006 18:53:03 +0300

Nick Cox wrote:
Well, now you tell us. Possibly some variant on this:
quietly { foreach v of var v6-v146 { levelsof `v', local(this) local all : list all | this }

local all : list sort all
foreach text of local all { local count = 0 foreach v of var var6-v146 { count if `v' == "`text'" local count = `count' + r(N)
}
noi di as txt "`text' `count'" }
}
Nick [email protected]
Nikolaos A. Patsopoulos

Nick Cox wrote:

Check out -tabm- from -tab_chi- on SSC.
Alternatively, an approach from first
principles is to -reshape long- so that this reduces to a two-way tabulation.
Nikolaos A. Patsopoulos


I've got a set of variables v6-v146, each one containing string values (unique values ~4500):

v6 v7 v8 v9 v10...
text1 text1 text3 text45 text1...
text5 text2 text1 text455 text1
.....

I want to count how many times each of the values appears
in at least
one of the v6-v146 in each row [observation], e.g. text1
appears at
least once in 7365obs.

How can achieve this?

I tried :
tabm v7-v146

I had to kill the process after few minutes (it's a 150MB database)

Then used:

tabm v7-v8 // just to see what will come up but that's what I got:
too many values
r(134);

The unique values for each var is 4364 from a total of 25725 observations
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Nick I believe that you answered my problem, however I cannot test it since " levelsof `v', local(this) " exceeds 800 items (if i get it right).

Nikos

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