@Miles, eigen-decomposition with asymmetric matrix doesn't always give real-value solutions, and it doesn't have the nice properties that symmetric matrix holds. Usually you want to symmetrize your asymmetric matrix in some way, e.g. see http://machinelearning.wustl.edu/mlpapers/paper_files/icml2005_ZhouHS05.pdf but as Sean mentioned, you can always compute the largest eigenpair with power method or some variations like pagerank, which is already implemented in graphx.
On Fri, Aug 8, 2014 at 2:50 AM, Sean Owen <so...@cloudera.com> wrote: > The SVD does not in general give you eigenvalues of its input. > > Are you just trying to access the U and V matrices? they are also > returned in the API. But they are not the eigenvectors of M, as you > note. > > I don't think MLlib has anything to help with the general eigenvector > problem. > Maybe you can implement a sort of power iteration algorithm using > GraphX to find the largest eigenvector? > > On Fri, Aug 8, 2014 at 4:07 AM, Chunnan Yao <yaochun...@gmail.com> wrote: > > Hi there, what you've suggested are all meaningful. But to make myself > > clearer, my essential problems are: > > 1. My matrix is asymmetric, and it is a probabilistic adjacency matrix, > > whose entries(a_ij) represents the likelihood that user j will broadcast > the > > information generated by user i. Apparently, a_ij and a_ji is different, > > caus I love you doesn't necessarily mean you love me(What a sad story~). > All > > entries are real. > > 2. I know I can get eigenvalues through SVD. My problem is I can't get > the > > corresponding eigenvectors, which requires solving equations, and I also > > need eigenvectors in my calculation.In my simulation of this paper, I > only > > need the biggest eigenvalues and corresponding eigenvectors. > > The paper posted by Shivaram Venkataraman is also concerned about > symmetric > > matrix. Could any one help me out? > > --------------------------------------------------------------------- > To unsubscribe, e-mail: user-unsubscr...@spark.apache.org > For additional commands, e-mail: user-h...@spark.apache.org > > -- Li @vrilleup
