Hi, I am working on a clustering problem which involves determining the largest "k" eigenvectors of a very large matrix. The matrices, I work on, are typically of the order of 10^6 by 10^6. Trying to do this using the Lanczos solver available in Mahout, I found it is very slow and takes around 1.5 minutes to compute each eigenvectors. Hence to get 4000 eigenvectors, it takes 100 hours or 4 days !!
So I am looking for something faster to solve the "Eigen decomposition" problem for very large sparse matrix. Please suggest me what should I use ? Thanks, Aniruddha
