Event Pattern Analysis: Peak Detection and Pattern Comparison

This article proposes two exploratory methods for analyzing event patterns. Events in this article refer to zero-dimensional objects in the spatiotemporal dimension, such as crimes, earthquakes, and traffic accidents. One method detects the peaks in event patterns, evaluates the degree of event concentration at the peaks, and visualizes its spatial variation. Another method evaluates the similarity between different event patterns and visualizes its spatial variation. The methods help us understand events' properties, consider their underlying mechanisms, and permit us to prevent events if they represent undesirable phenomena such as crimes and traffic accidents. The proposed methods are applied to analyze the population distribution in the central area of Tokyo in May 2019. The application revealed the spatial variation of population peaks in this area and the differences in population patterns between different types of days.