Binary β -hill climbing optimizer with S-shape transfer function for feature selection

Feature selection is an essential stage in many data mining and machine learning and applications that find the proper subset of features from a set of irrelevant, redundant, noisy and high dimensional data. This dimensional reduction is a vital task to increase classification accuracy and thus reduce the processing time. An optimization algorithm can be applied to tackle the feature selection problem. In this paper, a β-hill climbing optimizer is applied to solve the feature selection problem. β-hill climbing is recently introduced as a local-search based algorithm that can obtain pleasing solutions for different optimization problems. In order to tailor β-hill climbing for feature selection, it has to be adapted to work in a binary context. The S-shaped transfer function is used to transform the data into the binary representation. A set of 22 de facto benchmark real-world datasets are used to evaluate the proposed algorithm. The effect of the β-hill climbing parameters on the convergence rate is studied in terms of accuracy, the number of features, fitness values, and computational time. Furthermore, the proposed method is compared against three local search methods and ten metaheuristics methods. The obtained results show that the proposed binary β-hill climbing optimizer outperforms other comparative local search methods in terms of classification accuracy on 16 out of 22 datasets. Furthermore, it overcomes other comparative metaheuristics approaches in terms of classification accuracy in 7 out of 22 datasets. The obtained results prove the efficiency of the proposed binary β-hill climbing optimizer.