The common arithmetic operators such as ^ operate on the elements of matrices (or vectors or arrays). Similarly, * gives the element-wise product and not the matrix product.
I hope that this helps, John
At 04:40 PM 1/20/2004 +0000, Federico Calboli wrote:
Dear All,
I would like to ask why the zeroeth power of a matrix gives me a matrix of ones rather than the identity matrix:
> D<-rbind(c(0,0,0),c(0,0,0),c(0,0,0)) > D<-as.matrix(D) > D [,1] [,2] [,3] [1,] 0 0 0 [2,] 0 0 0 [3,] 0 0 0
> D^0 [,1] [,2] [,3] [1,] 1 1 1 [2,] 1 1 1 [3,] 1 1 1
I would have expected the identity matrix here.
I find the same result with every other square matrix I used. BTW, I am using R 1.8.1 on Linux Mandrake 9.1
Cheers,
Federico Calboli
____________________________ John Fox Department of Sociology McMaster University email: [EMAIL PROTECTED] web: http://www.socsci.mcmaster.ca/jfox
______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
