Quantitative Query Technology of Direction Relationships Based on Open Shape

Put forward the concepts of open trapezoid and open sector to extend the basic abstract class of open shape, and introduced the specific modeling method of direction relationships quantitative query with the extended open shapes. Based on the quantitative query technology under absolute reference framework, presented a universal method for direction relationships query under different reference frameworks both litative and quantitative queries. Finally, compared the open shape query method with the traditional range query method in performance of I/O cost and CPU cost.