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Re: st: RE: RE: Re: chi squared matrix


From   Daniel Egan <dp.egan@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: RE: RE: Re: chi squared matrix
Date   Mon, 22 Nov 2004 14:33:16 -0500

Thanks to Nick and Michael, but.....

While the makematrix worked correctly, I ran into an interesting
"quirk".  It is something I need to fix, but one of the indicators has
missing values for a substantial number of observations.)

This causes problems with makematrix in the following manner:

When I
tab2 ill_*, chi2
Stata goes variable by variable, and for those variables that have the
full 18k obs, uses all obs. when it comes to ill_problem crosstabs, it
reduces to 15k because of missings.

However, when doing
makematrix testchi, from(r(chi2)): tab2 ill_*, chi2
_all_ of the calculation are based on the smallest common sample size,
or the 15k.

This doesn't matter too much to me, since there shouldn't be missings
in the indicator, but it might be good to issue a caution about it.

FYI, the only reason I noticed was because the diagonal _was_ the
smaller observation size (15K). I do not know why the diagonal was the
number of observations - does this have to do with makematrix or chi2?

Cheers, and thanks again

Dan
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