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From |
Nick Cox <njcoxstata@gmail.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 17:11:46 +0000 |

I mean what is the element in row 1 and column 2 of your matrix? mat_s2[1,2] will display it in Mata. I may be missing something important, but I don't understand how your matrix can display like that unless it is symmetric. Nick On Thu, Nov 1, 2012 at 4:46 PM, Bianca B. <bianca268@yahoo.com> wrote: > 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/

**Follow-Ups**:**Re: st: Re: Stata matrix to Mata matrix form - Turn lower diagonal matrix***From:*"Bianca B." <bianca268@yahoo.com>

**References**:**Re: st: Re: Stata matrix to Mata matrix form***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: Re: Stata matrix to Mata matrix form - Turn lower diagonal matrix***From:*"Bianca B." <bianca268@yahoo.com>

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