Transformation of categorical features into real using low-rank approximations

Abstract

Most of existing machine learning techniques can handle objects described by real but not categorical features. In this paper we introduce a simple unsupervised method for transforming categorical feature values into real ones. It is based on low-rank approximations of collaborative feature value frequencies. Once object descriptions are transformed, any common real-value machine learning technique can be applied for further data analysis. For example, it becomes possible to apply classic and powerful Random Forest predictor in supervised learning problems. Our experiments show that a combination of the proposed features transformation method with common real-value supervised algorithms leads to the results that are comparable to the state-of-the-art approaches like Factorization Machines.