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# Re: st: Re: Stata matrix to Mata matrix form

 From "Bianca B." To statalist@hsphsun2.harvard.edu Subject Re: st: Re: Stata matrix to Mata matrix form Date Thu, 1 Nov 2012 08:39:34 -0700 (PDT)

```Nick, you're right, I'm sorry. I didn't specify that I need to turn my lower-triangular matrix into a symmetrical matrix by reflecting the lower triangular elements across the diagonal. So starting from this matrix

mat_S2

1   2
+---------+
1 |  0      |
2 |  1   0
|
+---------+
I'd like to obtain a matrix like that

1   2
+---------+
1 |  0   1  |
2 |  1   0  |
+---------+

--- On Thu, 11/1/12, Nick Cox <njcoxstata@gmail.com> wrote:

> From: Nick Cox <njcoxstata@gmail.com>
> Subject: Re: st: Re: Stata matrix to Mata matrix form
> To: statalist@hsphsun2.harvard.edu
> Date: Thursday, November 1, 2012, 8:29 AM
> Looks symmetric to me.
>
> If a matrix is symmetric, Stata says so, and only displays
> the lower
> half (including the principal diagonal).
>
> In your case, Stata is doing exactly that.
>
> Here is another example:
>
> . mata : I(3)
> [symmetric]
>
>    1   2   3
>     +-------------+
>   1 |  1          |
>   2 |  0   1      |
>   3 |
> 0   0   1  |
>     +-------------+
>
> If this is not what you mean, you'll have to explain what
> "doesn't
> work" means exactly.
>
> Nick
>
> On Thu, Nov 1, 2012 at 3:16 PM, Bianca B. <bianca268@yahoo.com>
> wrote:
> > Dear Nick,
> >
> > Thanks a lot. I converted a lower-triangular matrix
> from stata to mata form to apply the mata makesymmetric
> command but it doesn't work.
> > The command is
> >
> > : makesymmetric(mat_S2)
> > [symmetric]
> >        1   2
> >     +---------+
> >   1 |  0      |
> >   2 |  1   0
> |
> >     +---------+
> >
> > Would you have any suggestion?
> > Best,
> > Bianca
> >
> >
> >
> > . mat foo = J(6,7,42)
> >
> > . mat li foo
> >
> > foo[6,7]
> >     c1  c2  c3
> c4  c5  c6  c7
> > r1  42  42  42  42  42
> 42  42
> > r2  42  42  42  42  42
> 42  42
> > r3  42  42  42  42  42
> 42  42
> > r4  42  42  42  42  42
> 42  42
> > r5  42  42  42  42  42
> 42  42
> > r6  42  42  42  42  42
> 42  42
> >
> > . mata : mat_foo = st_matrix("foo")
> >
> > . mata : mat_foo
> >         1
> 2    3    4    5
> 6    7
> >
>    +------------------------------------+
> >   1 |
> 42   42   42   42   42   42   42
> |
> >   2 |
> 42   42   42   42   42   42   42
> |
> >   3 |
> 42   42   42   42   42   42   42
> |
> >   4 |
> 42   42   42   42   42   42   42
> |
> >   5 |
> 42   42   42   42   42   42   42
> |
> >   6 |
> 42   42   42   42   42   42   42
> |
> >
>    +------------------------------------+
> >
> > . mata : st_matrix("foo", mat_foo :/ 7)
> >
> > . mat li foo
> >
> > foo[6,7]
> >     c1  c2  c3
> c4  c5  c6  c7
> >
> r1   6   6   6   6   6   6   6
> >
> r2   6   6   6   6   6   6   6
> >
> r3   6   6   6   6   6   6   6
> >
> r4   6   6   6   6   6   6   6
> >
> r5   6   6   6   6   6   6   6
> >
> r6   6   6   6   6   6   6   6
> >
> > --- On Thu, 11/1/12, Bianca B. <bianca268@yahoo.com>
> wrote:
> >
> >> From: Bianca B. <bianca268@yahoo.com>
> >> Subject: Stata matrix to Mata matrix form
> >> To: statalist@hsphsun2.harvard.edu
> >> Date: Thursday, November 1, 2012, 7:25 AM
> >> Hi Stata users,
> >>
> >> Does anyone know how can I get stata matrix in mata
> matrix?
> *
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>

*
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```