共查询到20条相似文献,搜索用时 906 毫秒
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讨论了地图的基本元素及其拓扑关系.采用先建立子图拓扑关系,再以并运算方式产生图拓扑关系的思想。在实现方式上,以栅格影像为基础,用种子填充方式产生子图拓扑关系;采用面目标匹配法顺序搜索方式合并子图,生成图拓扑关系,并以自动方式实现上述思想. 相似文献
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讨论了地图的基本元素及其拓扑关系,采用先建立子图拓扑关系,再以并运算方式产生图拓扑关系的思想,在实现方式上,以栅格影像为基础,用种子填充方式产生子图拓扑关系;采用面目标匹配法序搜索方式合并子图,生成图拓扑关系,并以自动方式实现上述思想。 相似文献
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一种三维GIS矢量数据结构的研究--以矿山应用为例 总被引:18,自引:1,他引:17
本文针对传统数据结构的不足,借鉴二维矢量数据结构,并结合矿山实际情况,提出了用六组拓扑结构来刻划:点-结点,弧,环,曲面,体域和复杂地物之间的拓扑关系。引入“层次树”来动态维护这六组拓扑结构。最后针对一典型的矿山实体,给出了基于这六组拓扑结构的完整描述。实践证明:用本文所提出的六组拓扑结构能够很好地刻划出矿山实体的特点,“层次树”的引入则可大大减少数据维护所需的辅助操作。 相似文献
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为构建和表达顾及外拓扑的产权体,以现有楼层平面图为基础,采用"推拉"二维图形的方式生成产权体三维模型,并使用3-组合图表达产权体的内拓扑与外拓扑,提出基于带权关联图与关联矩阵的"推拉"间隔传递方法,基于老新间隔对照关系的组合图飞镖生成方法以及组合图β关系的添加算法。通过"推拉"平面图的方式可以生成产权体三维模型;3-组合图可以表达产权体的内拓扑和外拓扑,并能提高构体效率。 相似文献
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当前的排水管网拓扑模型由于忽略了排水管网的细节特征,致使拓扑关系过于简单,不能完成特定排水业务模型空间分析,在一定程度上阻碍了排水GIS系统的发展。基于图论理论,本文提出了城市排水GIS系统细致拓扑模型。首先,基于面向对象方法提出拓扑概念模型和逻辑模型,增加其拓扑关系描述的细节规则,以实现对客观世界的真实模拟。然后在数据结构设计中,采用十字链表作为存储结构,将其改进并与R+树进行关联生成空间索引。在空间分析中,本文基于R+索引和十字链表提出了空间查询和路径分析典型算法。最后以镇江市城市排水管网地理信息系统开发为例,对拓扑模型进行了开发实践。试验结果表明,本文提出的拓扑模型可以更真实模拟客观世界,提供更多种空间分析,完成海量数据快速访问,为实现城市排水GIS系统海量数据的高效空间分析提供解决方案。 相似文献
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本文介绍一种基于autoCAD图形数据的拓扑算法和LISP程序思路,可以快速地用单线数字化道路中心线.程序通过搜寻交通网络中每个独立的最小多边形.自动生成双线符号的道路图。 相似文献
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空间数据的拓扑关系及其自动生成 总被引:8,自引:0,他引:8
本文讨论了空间数据的拓扑关系,对地图的基本图形元素作了更准确的表述;详细介绍和讨论了自动生成空间数据拓扑关系的原理和方法,重点研究和探讨了并列和嵌套的面域拓扑关系。本文所述的方法适用于多种复杂的空间实体关系。 相似文献
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同一结点上弧-弧拓扑关系的建立对多边形的自动生成具有重要意义,为了更好地描述同一结点上弧段间的拓扑关系,本文在考虑算法效率、可靠性和稳定性的基础上,通过引入方向夹角和类方位角概念,提出并实现了一种建立结点上弧-弧拓扑关系的类方位角算法.为检验算法的有效性,选取两个城市的道路交通网络进行了拓扑构建实验,通过与传统角度算法... 相似文献
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基于道路网的结构分析,提出了一种高等级道路网拓扑自动保持方法,适用于任意提取的高等级路网。首先根据道路的连通关系生成对偶图,利用最小生成树保持道路网的整体连通性;然后使用广度优先搜索和最短路径计算进行悬挂弧段连接和合理路径连接,保持高等级道路网的导航连通性;最后通过实验验证了本文方法所保持的道路网拓扑结构的有效性。实验结果表明,通过本方法保持的拓扑关系能够保持道路网的整体连通性,反映道路网的高等级结构模式特征,而且与基于原始划分的高等级道路网所规划的最短路径相比,拓扑自动保持后的高等级道路网能够合理地反映道路结点之间的导航路径规划。 相似文献
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Polygonal object is a fundamental type of geometric data in vector GIS. The key step cleaning topological relationship after data collection of polygonal layer is to build polygonal objects from digital arcs. The raw digital arcs may intersect with each other. The algorithm for building polygonal objects after the raw arcs have been split at all intersections is presented. The build-up of polygonal objects in this paper is designed to be implemented by two steps. The first step is to extract all the polygons needed for build-up of polygonal objects from arcs. The second step is to organize polygonal objects from these polygons. For the first step, a tracing algorithm is proposed. The algorithm merely extracts the polygons needed for the build-up of polygonal objects, which is a subset of all the possible polygons that can be induced from the arcs. For the second step, an algorithm based on a specially designed order of polygons is advanced. All the topological relationships among the polygons are shown in a single scan. Experiments show that the two algorithms together offer a robust and efficient solution for building polygonal objects from intersected arcs. 相似文献
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WU HuayiWANG YandongGONG Jianya WU Huayi Associate Professor National Laooratory for momation tngineering in Surveying Mapping Remote Sensing Luoyu Road 《地球空间信息科学学报》1999,2(1):63-67
Polygonal object is a fundamental type of geometric data in vector GIS. The key step of cleaning topological relationship after data collection of polygonal layer is to build polygonal objects from digital arcs. The raw digital arcs may intersect with each other. The algorithm for building polygonal objects after the raw arcs have been split at all intersections is presented. The build-up of polygonal objects in this paper is designed to be implemented by two steps. The first step is to extract all the polygons needed for build-up of polygonal objects from arcs. The second step is to organize polygonal objects from these polygons. For the first step, a tracing algorithm is proposed. The algorithm merely extracts the polygons needed for the build-up of polygonal objects, which is a subset of all the possible polygons that can be induced from the arcs. For the second step, an algorithm based on a specially designed order of polygons is advanced. All the topological relationships among the polygons are sho 相似文献
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Up to now, detailed strategies and algorithms of automatic change detection for road networks based on GIS have not been discussed. This paper discusses two different strategies of automatic change detection for images with low resolution and high resolution using old GIS data, and presents a buffer detection and tracing algorithm for detecting road from low-resolution images and a new profile tracing algorithm for detecting road from high-resolution images. For feature-level change detection (FL-CD), a so-called buffer detection algorithm is proposed to detect changes of features. Some ideas and algorithms of using GIS prior information and some context information such as substructures of road in high-resolution images to assist road detection and extraction are described in detail. 相似文献
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SUIHaigang LIDeren GONGJianya 《地球空间信息科学学报》2003,6(4):44-50
Up to now, detailed strategies and algorithms of automatic change detection for road networks based on GIS have not been discussed. This paper discusses two different strategies of automatic change detection for images with low resolution and high resolution using old GIS data, and presents a buffer detection and tracing algorithm for detecting road from low-resolution images and a new profile tracing algorithm for detecting road from high-resolution images. For feature-level change detection (FL-CD), a so-called buffer detection algorithm is proposed to detect changes of features. Some ideas and algorithms of using GIS prior information and some context information such as substructures of road in high-resolution images to assist road detection and extraction are described in detail. 相似文献
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分析了GIS网络的基本要素和网络关系,提出了完备表达网络的TDN数据结构,从时间和空间效率上进行了推演,并以试验验证了该结构的实用性。 相似文献