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Re: st: Re: Stata matrix to Mata matrix form - Turn lower diagonal matrix
From
"Bianca B." <[email protected]>
To
[email protected]
Subject
Re: st: Re: Stata matrix to Mata matrix form - Turn lower diagonal matrix
Date
Thu, 1 Nov 2012 09:46:33 -0700 (PDT)
mat_S2[1,2] is the name of the matrix.
mat_S2
1 2
+---------+
1 | 0 |
| 1 0
|
> >+---------+
I found this old post
http://www.stata.com/statalist/archive/2007-02/msg00156.html
where there is exactly my same question that is to turn my lower-triangular matrix, named mat_S2, into a symmetrical matrix by reflecting the lower triangular elements across the diagonal.
I tried to use mata makesymmetric function but I do not obtain the matrix I wish and that I report below
1 2
+---------+
1 | 0 1 |
2 | 1 0 |
+---------+
--- On Thu, 11/1/12, Nick Cox <[email protected]> wrote:
> From: Nick Cox <[email protected]>
> Subject: Re: st: Re: Stata matrix to Mata matrix form
> To: [email protected]
> Date: Thursday, November 1, 2012, 9:34 AM
> You've lost me. What is mat_S2[1,2]?
>
> Nick
>
> On Thu, Nov 1, 2012 at 3:39 PM, Bianca B. <[email protected]>
> wrote:
> > 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 <[email protected]>
> wrote:
> >
> >> From: Nick Cox <[email protected]>
> >> Subject: Re: st: Re: Stata matrix to Mata matrix
> form
> >> To: [email protected]
> >> 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. <[email protected]>
> >> 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. <[email protected]>
> >> wrote:
> >> >
> >> >> From: Bianca B. <[email protected]>
> >> >> Subject: Stata matrix to Mata matrix form
> >> >> To: [email protected]
> >> >> 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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