On Sun, Mar 11, 2012 at 1:46 AM, Ebrahim Jahanshiri <e.jahansh...@gmail.com> wrote: > Dear list, > > I understand that to raise matrix A to power (-1/2) we should use something > like this: > > eigen(A)$vectors%*%diag(1/sqrt(eigen(A)$values))%*%t(eigen(A)$vectors) > > [from previous discussions: > http://r.789695.n4.nabble.com/matrix-power-td900335.html] > > But this will only do it for negative sqrt of the matrix not for other > fraction powers like (-3/2).
Not sure why you think this won't work for -3/2 - simply use eigen(A)$values^(-3/2) instead of the 1/sqrt(eigen(A)$values) and you're good to go. Generalizations to other powers are left as exercise for the reader :) Peter ______________________________________________ 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.
