Clustering by Nonparametric Smoothing
This provides a flexible, assumption-free clustering method for data analysis, though it appears incremental as it builds on nonparametric smoothing techniques.
The authors tackled clustering by framing it as a nonparametric smoothing problem to estimate cluster membership distributions, bypassing explicit modeling assumptions like Gaussian Mixture Models, and demonstrated strong performance on public datasets compared to benchmarks.
A novel formulation of the clustering problem is introduced in which the task is expressed as an estimation problem, where the object to be estimated is a function which maps a point to its distribution of cluster membership. Unlike existing approaches which implicitly estimate such a function, like Gaussian Mixture Models (GMMs), the proposed approach bypasses any explicit modelling assumptions and exploits the flexible estimation potential of nonparametric smoothing. An intuitive approach for selecting the tuning parameters governing estimation is provided, which allows the proposed method to automatically determine both an appropriate level of flexibility and also the number of clusters to extract from a given data set. Experiments on a large collection of publicly available data sets are used to document the strong performance of the proposed approach, in comparison with relevant benchmarks from the literature. R code to implement the proposed approach is available from https://github.com/DavidHofmeyr/CNS