Ouch. This is a fine place to start the conversation. Can you put exactly your message below into a bug report on JIRA at https://issues.apache.org/jira/browse/MAHOUT ?
That will help us track this apparent bug. On Sun, Feb 3, 2013 at 11:22 AM, Ceyhun Can ÜLKER <[email protected]>wrote: > Hello, > > I don't know if this is the right place to post, but here I go. Actually > this bug is probably about the viewColumn method, or matrixLike method or > MatrixVectorView constructor, I didn't really looked into it. But it is > easy to reproduce. > > I have a dense matrix U of size 10x670. When I try to do this I get a > cardinality exception, which doesn't make sense: > > Vector uI = U.viewColumn(i); > Matrix outerProduct = uI.cross(uI); > > Exception is thrown from AbstractMatrix class' cross method, when a row is > tried to be assigned in the result matrix. > public Matrix cross(Vector other) { > Matrix result = matrixLike(size, other.size()); > for (int row = 0; row < size; row++) { > result.assignRow(row, other.times(getQuick(row))); > } > return result; > } > > The problem here is matrixLike method does not return a 10x10 matrix as it > should, instead it returns 1x1 matrix. > > Hope this helps. > > Ceyhun Can Ülker >
