Hi All, I asked a question before but duffymo said it is not clear so i am going to post it again here. I am using Jama api for SVD calculation. I know very well about jama and SVD. Jama does not work if your column are more than rows. I have this situation. What should I do?? any help? I can't transpose the matrix too as it can produce wrong results. Thanks.
P.S: I am calculating LSI with the help of jama. I am going like column(docs) and rows ( terms )
Hi
If I understand correctly you are trying to compute the SVD of a matrix which is not square, and you have the library JAMA which only works on square matrices ? If I have understood you correctly then the answer to your question is obvious -- get a library which does compute SVD for non-square matrices. If I remember correctly Numerical Recipes contains such an algorithm, I expect you can find many other sources with Google.
Regards
Mark
Why not use transpose? If X = USV', then X' = VS'U'. Right?
Transpose your matrix. Get U, S and V. Transpose everything back.
Since you're doing LSI, you could use SVDLIBJ, which is the Java equivalent of SVDLIBC, which is one of the most scalable SVD implementations that is freely available. The S-Space package has a command-line tool for SVDLIBJ set up already. Also, you can use their Matrix libraries and avoid the command-line if that fits your needs better.