Analyzing the impact of data vectorization on distance relations

Some popular algorithms used in Music Information Retrieval (MIR) such as Self-Organizing Maps (SOMs) require the objects they process to be represented as vectors, i.e. elements of a vector space. This is a rather severe restriction and if the data does not adhere to it, some means of vectorization is required. As a common practice, the full distance matrix is computed and each row of the matrix interpreted as an artificial feature vector. This paper empirically investigates the impact of this transformation. Further, an alternative approach for vectorization based on Multidimensional Scaling is pro posed that is able to better preserve the actual distance relations of the objects which is essential for obtaining a good retrieval performance.