Sorry if this answer was already given, or if I miss the point,
but did you have a look to "lowerTriangle" and "upperTriangle" functions
in the "gdata" package ?
# example
# A<-matrix(rnorm(9),3,3)
# B<-B<-matrix(NA,dim(A)[1],dim(A)[2])
# lowerTriangle(B)<-lowerTriangle(A)
# upperTriangle(B)<-low
sity
> Hamilton, Ontario
> Canada L8S 4M4
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>
> > -Original Message-
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED] On Behalf Of Ranjan Maitra
> > Se
OTECTED] On Behalf Of Ranjan Maitra
> Sent: Thursday, April 19, 2007 9:28 PM
> To: r-help@stat.math.ethz.ch
> Subject: [R] how to convert the lower triangle of a matrix to
> a symmetricmatrix
>
> Hi,
>
> I have a vector of p*(p+1)/2 elements, essentially the lower
> tr
