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Re: st: re: Matrix question
From 
 
[email protected] (Brendan Halpin) 
To 
 
[email protected] 
Subject 
 
Re: st: re: Matrix question 
Date 
 
Mon, 06 Feb 2012 09:53:22 +0000 
Thanks, that's exactly what I was looking for!
On Mon, Feb 06 2012, Christopher Baum wrote:
> Probably some more elegant way of generating the transformation matrix, but:
>
> mata
> bigmat = runiform(15,6)
> trans = J(1, 5, 1/5)
> zer = J(1,5,0)
> transmat = (trans, zer, zer \ zer, trans, zer \ zer, zer, trans)
> reduced = transmat * bigmat
> bigmat
> reduced
> end
Yes, there's an easy way of generating the transformation matrix, which
is also easy to adapt for different sizes of the data matrix. 
mm_expand(diag(J(1, 3, 1/5)), J(1, 1, 1), J(1, 3, 5))
mm_expand is from Ben Jann's more_mata.
Brendan
-- 
Brendan Halpin,   Department of Sociology,   University of Limerick,   Ireland
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