M. Oliver and S. Vasylkevych,
Non-negative matrix factorization with factorizable feature matrix,
submitted for publication.

Abstract:

We study the following generalization of the classical non-negative matrix factorization (NMF) problem: Given a non-negative matrix V, i.e., a matrix with non-negative elements, find a low rank approximation VCWH where all right hand factors are non-negative, C is a given generally non-invertible "feature map," and V and H are low rank factors to be determined by best-approximation in a weighted Frobenius norm. We shall refer to this setting as the FFNMF problem. In this paper, we propose a non-multiplicatively regularized gradient descent algorithm for the FFNMF problem, prove its consistency, and show that a stationary or a limit point of the algorithm is a stationary point for the cost functional except possibly at the boundary of the admissible region, where the cost is then locally increasing when moving away from the boundary.
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