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Re: st: Transform matrices


From   u.atz@lse.ac.uk
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Transform matrices
Date   Mon, 20 Dec 2010 12:01:43 +0000

I like it, thanks.


>  
> More generally, you can use selection vectors:
> 
> *************************************
> clear*
> mat define A = (1, 2, 3, 4, 5, 6)'
> mata
> mA = st_matrix("A")
> st_matrix("B", (mA[2:*(1::length(mA)/2):-1,1], ///
> 	mA[2:*(1::length(mA)/2),1]))
> end
> mat list B
> *************************************
> 
> T
> 
> On Mon, Dec 20, 2010 at 1:40 AM, Tirthankar Chakravarty
> <
> tirthankar.chakravarty@gmail.com
> > wrote:
> > Using the Mata -rowshape()- function:
> >
> > *************************************
> > clear*
> > mat define A = (1, 2, 3, 4, 5, 6)'
> > mata: st_matrix("B", rowshape(st_matrix("A"), 3))
> > mat list B
> > *************************************
> >
> > T
> >
> > On Mon, Dec 20, 2010 at 1:24 AM,  <
> u.atz@lse.ac.uk
> > wrote:
> >> Dear matrix wizards,
> >>
> >> I tried to get a column vector into a matrix format, such as
> >>
> >> 1
> >> 2
> >> 3
> >> 4
> >> 5
> >> 6
> >>
> >>  into
> >>
> >> 1       2
> >> 3       4
> >> 5       6
> >>
> >> for a general specification.
> >>
> >> My clumsy solution was to create two loops
> >>
> >> clear
> >> mat def A = (1\ 2\ 3\ 4\ 5\ 6)
> >>
> >> forvalues n = 1(2)5 {
> >>        mat a`n' = A[`n', 1]
> >>        if `n' == 1     local m = "`n'"
> >>                else local m = "`m' \ `n'"
> >>        mat c1 = (`m')
> >> }
> >>
> >> forvalues n = 2(2)6 {
> >>        mat a`n' = A[`n', 1]
> >>        if `n' == 2     local k = "`n'"
> >>                else local k = "`k' \ `n'"
> >>        mat c2 = (`k')
> >> }
> >>
> >> mat B = (c1, c2)
> >>
> >> mat list B
> >>
> >>
> >> Surely there is a more elegant (and more general) way? Perhaps Mata is the solution?
> >>
> >> This is a rather academic exercise, but it would be nice if someone could share his/her potential code example.
> >>
> >> Cheers,
> >> Ulrich
> >>
> >>
> >> Please access the attached hyperlink for an important electronic communications disclaimer: 
> http://lse.ac.uk/emailDisclaimer
> 
> >>
> >> *
> >> *   For searches and help try:
> >> *   
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> 
> >> *   
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> 
> >> *   
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> 
> >>
> >
> >
> >
> > --
> > To every ω-consistent recursive class κ of formulae there correspond
> > recursive class signs r, such that neither v Gen r nor Neg(v Gen r)
> > belongs to Flg(κ) (where v is the free variable of r).
> >
> 
> 

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