JohnLangford/vowpal_wabbit — pull request #56 by stross (2012-10-01 20:46:27+00:00)
Title: Change to Normalized Update to properly handle non-zero initial weight

I updated the sparse_dense.cc functions so that when the range of a feature increases, we only rescale the current weight vector when the current range is non-zero. That way the first time we see a feature, the weight vector is not rescaled, and not reset to 0 as previously (since the rescaling factor is old range/new range)