关键词: 梯形分割, 点面包含分析, 空间分析, 地理信息系统

Abstract: Point-in-polygon analysis has a broad range of application in many research fields.Firstly，some existing methods determining whether a point is in a polygon have been analyzed，and then，a new algorithm that based on the trapezoidal decomposition has been proposed.This algorithm decomposes the polygons into a series of trapezoidal units，so that the point-in-polygon analysis has been transformed into the problem of determining whether a point is in a trapezoidal unit.This method has already been applied to a GIS platform software，and the test results prove that this algorithm is of great stability and reliability.Moreover，it can be adapted to any complex polygons（with inner hole），with no need to process the abnormal conditions.

Key words: trapezoidal decomposition, point-in-polygon analysis, spatial analysis, geographic information system