R help - Feb 2012 - Fiedler

Hi.

I am looking for a function in R for computing the Fiedler vector of a graph
(the eigenvector associated with the second smallest eigenvalue of the Laplacian
of the graph). Alternatively, I am searching for an efficient method to compute
just few eigenvalues/vectors of a matrix (the smallest).

Many thanks.

Massimo Franceschet

Hola!

This can be done with the CRAN package igraph, which contains (part
of) the arpack
library for computing only some eigenvalues/eigenvectors of sparse
matrices. arpack gives you the option of computing a few of the
smallest or a few of the largest eigenvalues/vectors.

Do
library(igraph)
?arpack

Kjetil

On Thu, Feb 2, 2012 at 12:29 PM, Massimo Franceschet
<massimo.franceschet at uniud.it> wrote:
> Hi.
>
> I am looking for a function in R for computing the Fiedler vector of a
graph (the eigenvector associated with the second smallest eigenvalue of the
Laplacian of the graph). Alternatively, I am searching for an efficient method
to compute just few eigenvalues/vectors of a matrix (the smallest).
>
> Many thanks.
>
> Massimo Franceschet
> ______________________________________________
> R-help at 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.