tri.mesh(tripack)
tri.mesh()所属R语言包：tripack
Create a delaunay triangulation
建立Delaunay三角网的
译者：生物统计家园网 机器人LoveR
描述----------Description----------
This subroutine creates a Delaunay triangulation of a set of N arbitrarily distributed points in the plane referred to as nodes. The Delaunay triangulation is defined as a set of triangles with the following five properties:
此子例程创建一个的平面内的一组任意分布的N点称为节点的Delaunay三角剖分。的Delaunay三角剖分的定义为一组的三角形与下列五个属性：
1) The triangle vertices are nodes.
1）三角形顶点的节点。
2) No triangle contains a node other than its vertices.
2）没有三角形包含其顶点以外的一个节点。
3) The interiors of the triangles are pairwise disjoint.
3）内部的三角形是两两相交。
4) The union of triangles is the convex hull of the set of nodes (the smallest convex set which contains the nodes).
4）的三角形的工会是节点的集合（最小的凸集其中包含的节点）的凸包。
5) The interior of the circumcircle of each triangle contains no node.
5）内部的每个三角形的外接圆不包含节点。
The first four properties define a triangulation, and the last property results in a triangulation which is as close as possible to equiangular in a certain sense and which is uniquely defined unless four or more nodes lie on a common circle. This property makes the triangulation well-suited for solving closest point problems and for triangle-based interpolation.
前四个属性定义一个三角，一个三角的最后一个属性的结果是尽可能接近等角在一定意义上，这是唯一定义的，除非在同一圆周上4个或更多的节点所在。此属性使得非常适合于求解最近点问题和三角形为基础的内插的三角剖分。
The triangulation can be generalized to a constrained Delaunay triangulation by a call to add.constraint. This allows for user-specified boundaries defining a nonconvex and/or multiply connected region.
三角网，可推广到一个约束Delaunay三角网的调用add.constraint。这允许用户指定的边界定义一个非凸和/或多个连接的区域。
The operation count for constructing the triangulation is close to O(N) if the nodes are presorted on X or Y components. Also, since the algorithm proceeds by adding nodes incrementally, the triangulation may be updated with the addition (or deletion) of a node very efficiently. The adjacency information representing the triangulation is stored as a linked list requiring approximately 13N storage locations.
建设三角的操作数是接近O（N），如果X或Y分量的节点上进行了预先排序。另外，由于通过增加节点增量算法进行三角剖分可以与一个节点加入（或删除）的非常有效地更新。代表三角邻接信息存储作为一个链表需要约13N存储位置。
用法----------Usage----------
tri.mesh(x, y = NULL, duplicate = "error")
参数----------Arguments----------
参数：x
vector containing x coordinates of the data. If y is missing x should contain two elements $x and $y.
矢量包含x坐标的数据。如果y失踪x应该包含两个元素$x和$y。
参数：y
vector containing y coordinates of the data.
向量的y坐标的数据。
参数：duplicate
flag indicating how to handle duplicate elements. Possible values are: "error" – default, "strip" – remove all duplicate points, "remove" – leave one point of duplicate points.
标志指示如何处理重复的元素。可能的值是："error" - 默认情况下，"strip" - 删除所有重复点，"remove" - 留下一个点重复点。
值----------Value----------
An object of class "tri"
对象的类"tri"
参考文献----------References----------
R. J. Renka (1996). Algorithm 751: TRIPACK: a constrained two-dimensional Delaunay triangulation package. ACM Transactions on Mathematical Software. 22, 1-8.
参见----------See Also----------
tri, print.tri, plot.tri, summary.tri, triangles, convex.hull, neighbours, add.constraint.
tri，print.tri，plot.tri，summary.tri，triangles，convex.hull，neighbours，add.constraint。
实例----------Examples----------
data(tritest)
tritest.tr<-tri.mesh(tritest$x,tritest$y)
tritest.tr
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注：
注1：为了方便大家学习，本文档为生物统计家园网机器人LoveR翻译而成，仅供个人R语言学习参考使用，生物统计家园保留版权。
注2：由于是机器人自动翻译，难免有不准确之处，使用时仔细对照中、英文内容进行反复理解，可以帮助R语言的学习。
注3：如遇到不准确之处，请在本贴的后面进行回帖，我们会逐渐进行修订。
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发表于 2012-10-1 12:10:13
