data transformation non-negative matrix factorization Non negative matrix factorization is a data transformation in which factorises a matrix and which forces that all elements must be equal to or greater than zero. Non-negative matrix factorization is used in text mining where document-term matrix is constructed with the weights of various terms (typically weighted word frequency information) from a set of documents. This matrix is factored into a term-feature and a feature-document matrix. http://en.wikipedia.org/wiki/Non-negative_matrix_factorization non-negative matrix factorization metadata complete