排序方式： 共有26条查询结果，搜索用时 15 毫秒
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基于最短路径的扩展泰森多边形建立 总被引：2，自引：1，他引：2
由于传统的泰森多边形是对空间不考虑路径距离的一种分割方式，使得其在很多领域的应用受到了限制，尤其是在城市规划和沿路径分析等方面表现更为突出。针对这种情况，文中提出一种基于最短路径的扩展泰森多边形的建立方法，并对这种泰森多边形的应用前景提出了自己的看法。 相似文献
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自动搜索最小多边形算法的研究 总被引：2，自引：1，他引：2
多边形的自动搜索是ＧＩＳ空间分析的基本算法之一，同时也在地籍拆宗、导线网闭合环的闭合差计算等领域有着重要的作用。本文依据一般的图形数据结构，提出了一种结点标记的搜索算法，利用该算法可自动搜索出所有独立的最小多边形。 相似文献
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遥感影像制图综合的智能化研究 总被引：2，自引：0，他引：2
本文以人工智能为基础,用计算机模拟一般制图人员对遥感图像进行制图综合的过程,用框架的知识表示方法建立了一个实验性的知识库,并设计了一个推理机。对蒙古人民共和国乌布苏淖尔地区的ＴＭ分类图进行了实验,取得了较好的效果。 相似文献
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Conventional algorithms for polygon rasterization are typically designed to maintain non-topological characteristics. Consequently, topological relationships, such as the adjacency between polygons, may also be lost or altered, creating topological errors. This paper proposes a topology-preserving polygon rasterization algorithm to avoid topological errors. Four types of topological error may occur during polygon rasterization. The algorithm starts from an initial polygon rasterization and uses a set of preserving strategies to increase topological accuracy. The count of the four types of error measures the topological errors of the conversion. Topological accuracy is summarized as 1 minus the ratio of actual topological errors to the total number of possible error cases. When applied to a land-use dataset with a data volume of 128 MB, 127,836 polygons, and extending 1352 km2, the algorithm achieves a topological accuracy of more than 99% when raster cell size is 30 m or smaller (100% for 5 and 10 m). The effects of cell size, polygon shape, and number of iterations on topological accuracy are also examined. 相似文献
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本文提出了从栅格数据直接建立拓扑关系的思想,用跟踪过程中容易获得的拓扑信息来优化拓扑生成的算法模型,借以提高拓扑生成的效率。本文还提出用连通性区域填充的方法处理各种任意复杂岛的思想。 相似文献
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射线法判定点与多边形包含关系的改进 总被引：2，自引：0，他引：2
提出了一种完整的判定点与多边形包含关系的算法, 它克服了定向射线法判定点与多边形包含关系的缺点。这种算法易于理解、运算简单、效率高。 相似文献
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Chen Zhou Zhenjie Chen 《International journal of geographical information science》2018,32(12):2402-2426
Polygon intersection is an important spatial data-handling process, on which many spatial operations are based. However, this process is computationally intensive because it involves the detection and calculation of polygon intersections. We addressed this computation issue based on two perspectives. First, we improved a method called boundary algebra filling to efficiently rasterize the input polygons. Polygon intersections were subsequently detected in the cells of the raster. Owing to the use of a raster data structure, this method offers advantages of reduced task dependence and improved performance. Based on this method, we developed parallel strategies for different procedures in terms of workload decomposition and task scheduling. Thus, the workload across different parallel processes can be balanced. The results suggest that our method can effectively accelerate the process of polygon intersection. When addressing datasets with 1,409,020 groups of overlapping polygons, our method could reduce the total execution time from 987.82 to 53.66 s, thereby obtaining an optimal speedup ratio of 18.41 while consistently balancing the workloads. We also tested the effect of task scheduling on the parallel efficiency, showing that reducing the total runtime is effective, especially for a lower number of processes. Finally, the good scalability of the method is demonstrated. 相似文献
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采用了双向链表这种数据结构,对两简单多边形的顶点及交点进行存储,在对交点进行插入时,可直接插入链表中,避免了利用单向链表或数组进行存储时对点的重复查找。通过遍历两个顶点、交点混合表,可得到两多边形的交及多边形的顶点,从而得到两多边形的交集。相对其他类似的算法,该算法具有较快的计算速度和较高的效率。 相似文献