Research on discrete points of electric field model for conflict detection and displacement

Conflict detection and displacement are significant operators to maintain spatial relationship of map elements in cartography. At present, much attention has been paid to element division for local conflict detection and progressive displacement. By deeply observation, analysis and experiment, many models have been found good applicability for cartography, such as structure mechanics model, snake model, delaunay model, et al. But local conflict detection and progressive displacement still need more researches to achieve automatic cartographic generalization. In this paper, electric field model is proposed firstly to try conflict detection and displacement. Distribution of electric field is suit for conflict detection and displacement of map elements, since conflict occurs in local and changes with range. The main idea is to take conflict of road and building elements as that of points scattered from lines, and points represent particles with electric power. Conflict can be expressed by electric repulsion between particles. On the basis of electric field model, an algorithm and workflow is designed to verify the model effectiveness. The experiment concludes that the quantitative relationship of scale factor to discretization step and displacement amount is credible, and progressive displacement algorithm is effective for conflict detection and displacement.