Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
From | "Bianca B." <bianca268@yahoo.com> |
To | statalist@hsphsun2.harvard.edu |
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 <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, 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. <bianca268@yahoo.com> > 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 <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? > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/faqs/resources/statalist-faq/ > * http://www.ats.ucla.edu/stat/stata/ > * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/