Marco Visser wrote: > Dear R users & Experts, > > This is just a curiousity, I was wondering why the dominant eigenvetor and > eigenvalue > of the following matrix is given as the third. I guess this could complicate > automatic selection > procedures. > > 0 0 0 0 0 5 > 1 0 0 0 0 0 > 0 1 0 0 0 0 > 0 0 1 0 0 0 > 0 0 0 1 0 0 > 0 0 0 0 1 0 > > Please copy & paste the following into R; > > a=c(0,0,0,0,0,5,1,0,0,0,0,0,0,1,0,0,0,0,0,0,1,0,0,0,0,0,0,1,0,0,0,0,0,0,1,0) > mat=matrix(a, ncol=6,byrow=T) > eigen(mat) > > The matrix is a population matrix for a plant pathogen (Powell et al 2005). > > Basically I would really like to know why this happens so I will know if it > can occur > again. > > Thanks for any comments, > > Marco Visser > > > Comment: In Matlab the the dominant eigenvetor and eigenvalue > of the described matrix are given as the sixth. Again no idea why. > ????
I get > eigen(mat)$values [1] -0.65383+1.132467i -0.65383-1.132467i 0.65383+1.132467i 0.65383-1.132467i [5] -1.30766+0.000000i 1.30766+0.000000i > Mod(eigen(mat)$values) [1] 1.307660 1.307660 1.307660 1.307660 1.307660 1.307660 So all the eigenvalues are equal in modulus. What makes you think one of them is "dominant"? ______________________________________________ R-help@stat.math.ethz.ch 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.
