扇形缓冲区的算法设计中国图象图形学报.DOC

中图法分类号: P208 文献标识码:A 文章编号:1006-8961(年) - 文章索引信息： 点要素扇形缓冲区的设计与应用( 侯景伟，孔云峰，张迪，吕可文 (河南大学环境与规划学院，河南 开封475004；河南大学中澳地理信息分析与应用研究所ISegmentCollection实例；最后，绘制出扇形缓冲区并进行多边形叠置处理。为了便于使用该功能，并能进行多种方法和参数选择，开发了扇形缓冲区向导。最后，用两个实例证明了扇形缓冲区使用的方便性、动态性和有效性及其广阔的应用前景。扇形缓冲区是圆形缓冲区的一种扩充，包含了更多的信息和规律，便于分析和得出更可靠的结论，从而为管理者提供更准确的决策支持，同时丰富了空间分析中缓冲区的理论和方法。 关键词：ArcObjects；点要素；扇形缓冲区；地理信息系统 Design and applications of sector buffer for point feature Hou Jingwei, Kong Yunfeng, Zhang Di, Lv Kewen (College of Environment Planning, Henan University, Kaifeng 475004; China-Australia Cooperative Research Center for Geographic Information Analysis and Applications , Kaifeng 475004, China) Abstract: Traditionally, buffer zones of point features are circles with multiple radii which mean the same effect within the same radius around a point feature. In fact, a region affected by a point feature is possibly a sector buffer zone, not a circle one, due to some affected factors such as wind direction, mountain range, ocean, transportation and so forth. The objective of this study is to enrich theory and method of buffer zone in GIS spatial analysis so as to meet the need of analyzing sector buffer zone for point features. Sector buffer zone was discussed with respect to its definition, data structure, fundamental, algorithm and perspective of application. To analyze point feature with sector buffer zone, a module was developed with Visual Basic.NET and ArcObjects within ARC\INFO 9.3. After creating a polygon layer, iteratively, the layer field values were read out, and the coordinates of the arc endpoints and chord length were calculated, then the arc and two edges of the sector were added, respectively, into the instance defined by ISegmentCollection which then assigned to feature shape. If necessarily, the polygons overlaid were dealt with. Sector buffer wizards with 5 forms were developed to select different methods and parameters conveniently according to different demands. The wizard provided more choices