Feature Selection for Polymer Informatics: Evaluating Scalability and Robustness of the FS4RVDD Algorithm Using Synthetic Polydisperse Data Sets

The feature selection (FS) process is a key step in the Quantitative Structure Property Relationship (QSPR) modeling of physicochemical properties in cheminformatics. In particular, the inference of QSPR models for polymeric material properties constitutes a complex problem because of the uncertainty introduced by the polydispersity of these materials. The main challenge is how to capture the polydispersity information from the molecular weight distribution (MWD) curve to achieve a more effective computational representation of polymeric materials. To date, most of the existing QSPR techniques use only a single molecule to represent each of these materials, but polydispersity is not considered. Consequently, QSPR models obtained by these approaches are being oversimplified. For this reason, we introduced in a previous work a new FS algorithm called Feature Selection for Random Variables with Discrete Distribution (FS4RV(DD)), which allows dealing with polydisperse data. In the present paper, we evaluate both the scalability and the robustness of the FS4RV(DD) algorithm. In this sense, we generated synthetic data by varying and combining different parameters: the size of the database, the cardinality of the selected feature subsets, the presence of noise in the data, and the type of correlation (linear and nonlinear). Moreover, the performances obtained by FS4RV(DD) were contrasted with traditional FS techniques applied to different simplified representations of polymeric materials. The obtained results show that the FS4RV(DD) algorithm outperformed the traditional FS methods in all proposed scenarios, which suggest the need of an algorithm such as FS4RV(DD) to deal with the uncertainty that polydispersity introduces in human-made polymers.