On 4/23/2009 4:50 AM, Abelian wrote:
Dear All i have a little puzzle about eigenvector in the R. As we know that the eigenvector can be displayed on several form. For exampleA=matrix(c(1,2,4,3),2,2) if we want to get the eigenvalue and eigenvector, the code followed eigen(A) $values [1] 5 -1 $vectors [,1] [,2] [1,] -0.7071068 -0.8944272 [2,] -0.7071068 0.4472136 however, we also can calculate the vector matrix such that $vectors [,1] [,2] [1,] 0.7071068 -0.8944272 [2,] 0.7071068 0.4472136 or $vectors [,1] [,2] [1,] -0.7071068 0.8944272 [2,] -0.7071068 -0.4472136 or $vectors [,1] [,2] [1,] 0.7071068 0.8944272 [2,] 0.7071068 -0.4472136 my puzzle is that what does the rule be followed in R? On the other word, what does it make the R to display the first form? thanks a lot.
It's an arbitrary choice. See the note at the end of the Value section in ?eigen.
Duncan Murdoch ______________________________________________ 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.
