DBSCAN Speedup for Time-Serpentine Datasets

An approach to speed up the DBSCAN algorithm is suggested. The planar clusters to be revealed are assumed to be tightly packed and correlated constituting, thus, a serpentine dataset developing rightwards or leftwards as time goes on. The dataset is initially divided into a few sub-datasets along the time axis, whereupon the best neighbourhood radius is determined over the first sub-dataset and the standard DBSCAN algorithm is run over all the sub-datasets by the best neighbourhood radius. To find the best neighbourhood radius, it is necessary to know ground truth cluster labels of points within a region. The factual speedup registered in a series of 80 000 dataset computational simulations ranges from 5.0365 to 724.7633 having a trend to increase as the dataset size increases.