And, of course, I messed up that example as well by
not reinitializing the matrix. It should be
> test[lower.tri(test)] <- NA
> test
[,1] [,2] [,3] [,4]
[1,] NA 1 2 3
[2,] NA NA 4 5
[3,] NA NA NA 6
[4,] NA NA NA NA
> test[lower.tri(test)] <- t(test)[lower.tri(test)] # a correct solution
> test
[,1] [,2] [,3] [,4]
[1,] NA 1 2 3
[2,] 1 NA 4 5
[3,] 2 4 NA 6
[4,] 3 5 6 NA
Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com
From: R. Michael Weylandt [mailto:michael.weyla...@gmail.com]
Sent: Monday, September 26, 2011 1:30 PM
To: William Dunlap; r-help; m.marcinmichal
Subject: Re: [R] Triangular matrix upper to down
Nope, I was sloppy and missed that. Thanks
... forwarding to list and OP
Michael
On Mon, Sep 26, 2011 at 4:26 PM, William Dunlap
<wdun...@tibco.com<mailto:wdun...@tibco.com>> wrote:
My r-help mail is arriving out of order, so perhaps
you have already corrected this, but you need a call
to t() to make this work. Your solution does not
give a symmetric matrix (which I think the OP wants):
> test[lower.tri(test)] <- test[upper.tri(test)]
> print(test)
[,1] [,2] [,3] [,4]
[1,] NA 1 2 3
[2,] 1 NA 4 5
[3,] 2 3 NA 6
[4,] 4 5 6 NA
but the following does
> test[lower.tri(test)] <- t(test)[upper.tri(test)]
> print(test)
[,1] [,2] [,3] [,4]
[1,] NA 1 2 3
[2,] 1 NA 4 5
[3,] 2 4 NA 6
[4,] 3 5 6 NA
Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com<http://tibco.com>
> -----Original Message-----
> From: r-help-boun...@r-project.org<mailto:r-help-boun...@r-project.org>
> [mailto:r-help-boun...@r-project.org<mailto:r-help-boun...@r-project.org>] On
> Behalf Of R. Michael
> Weylandt
> Sent: Monday, September 26, 2011 1:10 PM
> To: m.marcinmichal; r-help
> Subject: Re: [R] Triangular matrix upper to down
>
> On Mon, Sep 26, 2011 at 4:09 PM, R. Michael Weylandt <
> michael.weyla...@gmail.com<mailto:michael.weyla...@gmail.com>> wrote:
>
> > How about: test[lower.tri(test)] <- test[upper.tri(test)]
> >
> > Try it with this data so you can see that it actually works: (the ones
> > obscure possible false solutions)
> >
> >
> > test <- matrix(ncol = 4, nrow = 4)
> > test[1, ] <- c(NA,1,2,3)
> > test[2, ] <- c(NA,NA,4,5)
> > test[3, ] <- c(NA,NA,NA,6)
> >
> > test[4, ] <- c(NA,NA,NA,NA)
> >
> > print(test)
> > test[lower.tri(test)] <- test[upper.tri(test)]
> > print(test)
> >
> > Hope this helps,
> >
> > Michael Weylandt
> >
> >
> >
> > On Mon, Sep 26, 2011 at 3:50 PM, m.marcinmichal
> > <m.marcinmic...@gmail.com<mailto:m.marcinmic...@gmail.com>>wrote:
> >
> >> Hi,
> >> suppose that we have a triangular upper matrix A
> >>
> >> test <- matrix(ncol = 4, nrow = 4)
> >> test[1, ] <- c(NA,1,1,1)
> >> test[2, ] <- c(NA,NA,1,1)
> >> test[3, ] <- c(NA,NA,NA,1)
> >> test[4, ] <- c(NA,NA,NA,NA)
> >>
> >> I know how quickly set diagonal value diag(test) <- 1. But how quickly set
> >> down value i.e. matrix is symmetrical? Is there in r project any quickly
> >> function?
> >>
> >> Thanks,
> >>
> >> Best
> >>
> >> Marcin
> >>
> >> --
> >> View this message in context:
> >> http://r.789695.n4.nabble.com/Triangular-matrix-upper-to-down-tp3845107p3845107.html
> >> Sent from the R help mailing list archive at Nabble.com.
> >>
> >> ______________________________________________
> >> R-help@r-project.org<mailto:R-help@r-project.org> mailing list
> >> https://stat.ethz.ch/mailman/listinfo/r-help
> >> PLEASE do read the posting guide
> >> http://www.R-project.org/posting-guide.html
> >> and provide commented, minimal, self-contained, reproducible code.
> >>
> >
> >
>
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>
> ______________________________________________
> R-help@r-project.org<mailto:R-help@r-project.org> mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
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