I am trying to check the results from an Eigen decomposition and I need to force a scalar multiplication. The fundamental equation is: Ax = lx. Where 'l' is the eigen value and x is the eigen vector corresponding to the eigenvalue. 'R' returns the eigenvalues as a vector (e <- eigen(A); e$values). So in order to 'check' the result I would multiply the eigenvalues ('l') by the eigenvectors. But unless I do it one by one (say e$values[1] * e$vectors[,1]) 'R' tries a matrix multiplication and that is not what I want. I would like a matrix that is formed by the SCALAR multiplication of each of the values by the corresponding eigenvector. How can I force such a multiplication? Thank you. Kevin
I am trying to check the results from an Eigen decomposition and I need to force a scalar multiplication. The fundamental equation is: Ax = lx. Where 'l' is the eigen value and x is the eigen vector corresponding to the eigenvalue. 'R' returns the eigenvalues as a vector (e <- eigen(A); e$values). So in order to 'check' the result I would multiply the eigenvalues ('l') by the eigenvectors. But unless I do it one by one (say e$values[1] * e$vectors[,1]) 'R' tries a matrix multiplication and that is not what I want. I would like a matrix that is formed by the SCALAR multiplication of each of the values by the corresponding eigenvector. How can I force such a multiplication? Thank you. Kevin
t(e$values * t(e$vectors)) Uwe Ligges On 25.06.2010 20:42, rkevinburton at charter.net wrote:> I am trying to check the results from an Eigen decomposition and I need to force a scalar multiplication. The fundamental equation is: Ax = lx. Where 'l' is the eigen value and x is the eigen vector corresponding to the eigenvalue. 'R' returns the eigenvalues as a vector (e<- eigen(A); e$values). So in order to 'check' the result I would multiply the eigenvalues ('l') by the eigenvectors. But unless I do it one by one (say e$values[1] * e$vectors[,1]) 'R' tries a matrix multiplication and that is not what I want. I would like a matrix that is formed by the SCALAR multiplication of each of the values by the corresponding eigenvector. How can I force such a multiplication? > > Thank you. > > Kevin > > ______________________________________________ > 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.