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# Re: st: Transform matrices

 From Tirthankar Chakravarty To statalist@hsphsun2.harvard.edu Subject Re: st: Transform matrices Date Mon, 20 Dec 2010 01:49:59 -0800

```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:
>> *   http://www.stata.com/help.cgi?search
>> *   http://www.stata.com/support/statalist/faq
>> *   http://www.ats.ucla.edu/stat/stata/
>>
>
>
>
> --
> 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).
>

--
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).

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/
```