Mining spatial high-average utility co-location patterns from spatial data sets

Abstract

The spatial co-location pattern refers to a subset of non-empty spatial features whose instances are frequently located together in a spatial neighborhood. Traditional spatial co-location pattern mining is mainly based on the frequency of the pattern, and there is no difference in the importance or value of each spatial feature within the pattern. Although the spatial high utility co-location pattern mining solves this problem, it does not consider the effect of pattern length on the utility. Generally, the utility of the pattern also increases as the length of the pattern increases. Therefore, the evaluation criterion of the high utility co-location mining is unfair to the short patterns. In order to solve this problem, this paper first considers the utility and length of the co-location pattern comprehensively, and proposes a more reasonable High-Average Utility Co-location Pattern (HAUCP). Then, we propose a basic algorithm based on the extended average utility ratio of co-location patterns to mining all HAUCPs, which solves the problem that the average utility ratio of patterns does not satisfy the downward closure property. Next, an improved algorithm based on the local extended average utility ratio is developed which effectively reduces the search space of the basic algorithm and improves the mining efficiency. Finally, the practicability and robustness of the proposed method are verified based on real and synthetic data sets. Experimental results show that the proposed algorithm can effectively and efficiently find the HAUCPs from spatial data sets.