Hi all, I'm trying to implement Latent Semantic Indexing using the mahout ssvd tool, and I'm having trouble understanding how I can use the output of ssvd Mahout to 'fold' new queries (documents) into the LSI space. Specifically, I can't find a way to multiply a vector representing a query by the inverse of the matrix of singular values - I can't find a way to solve for the inverse of the diagonal matrix of singular values.
I can generate the output matrices using ssvd, and compare document/term vectors using cosine similarity, but I'm stumped when it comes to folding a new document into the space. Any thoughts or guidance would be appreciated. Cheers, Chris
