ShortestPathFinder

Lines defining the network in which to find a path or paths. Input line features must be a topologically noded network with features connecting at line ends only. That is, all features must be split at junctions.

TheFrom-Toline contains vertices that define the source and destination nodes in the network. It can contain intermediate stops before the final destination. For example, aFrom-To线可以用于从A到B到B到D的路径。这也可以被读为“来自A通过B和C的路径。From-Tolines can be created by connecting points together to form a line, using thePointConnector或者VertexCreatortransformers.

For eachFrom-Toline, if a path is found it will be output as a single feature through thePath港口。This output feature contains the attributes and coordinate system of the originalFrom-To线。输出特征的几何形状由形成最短路径的网络的所有部分组成。请注意，如果Cost Typeis set toBy One Attribute或者By Two Attributesthen the “shortest path” is the one where the sum of the values of the applicableCost Attribute值最少。

如果给定的一个路径找不到From-To线，那么这个From-Toline will be output through the不path端口作为保留原始的功能From-Toattributes but has no geometry.

All other linear features that are not used as part of the shortest path are output through theUnused港口。

所有输入端口的所有非线性功能都会通过port, as are anyFrom-Tolines that have a negative cost(whenCost Typeis set toBy One Attribute或者By Two Attributes).

默认行为是使用整个输入功能作为组。此选项允许您选择定义要形成的组的属性。您可以从两者中选择属性Network和From-Toinput features.

笔记：平行处理如何与FME一起使用：见About Parallel Processingfor detailed information.

This parameter determines whether or not the transformer should perform the work across parallel processes. If it is enabled, a process will be launched for each group specified by theGroup Byparameter.

Parallel Processing Levels

例如，在四核机器上，最小的并行性将导致两个同时的FME进程。8核机上的极端并行性将导致16个同时流程。

您可以尝试此功能，并在Windows任务管理器和Workbench日志窗口中查看信息。

Yes: This transformer will process input groups in order. Changes on the value of theGroup Byparameter on the input stream will trigger batch processing on the currently accumulating group. This will improve overall speed if groups are large/complex, but could cause undesired behavior if input groups are not truly ordered.

不：这是默认行为。只有在存在所有输入时，处理将在此变换器中发生。

IfCost Typeis set to按长度或者By One Attribute, then the cost of each input line is set to the length of the line or the attribute value specified in theForward Cost Attribute. In this case, the algorithm will only consider the original orientation of the lines when finding the shortest path.

IfCost Typeis set toBy Two Attributes, then the shortest path algorithm will consider both directions of the input lines. The original orientation of the input line has the cost specified in theForward Cost Attribute和the reversed orientation of the input line has the cost specified in theReverse Cost Attribute.

The values that result fromCost Type与所有输入线一起求和From-Toline, and the shortest sum becomes the shortest-found path.

This parameter is used whenCost Typeis set toBy One Attribute或者By Two Attributes.

This parameter is used whenCost Typeis set toBy Two Attributes.

When specified, this attribute list that will hold the attributes for each inputNetworkfeature that make upPath输出功能。

This list also contains a_directionattribute that stores the direction of the segment of the shortest path as compared to its originalNetworkfeature. It will either be “same” or “opposite”, depending if the originalNetwork功能必须逆转或不逆转。

选择Yesto snap the points of theFrom-To到最接近的端点Networklines. The points are only snapped to the network lines if they are within the tolerance specified inSnapping Tolerance.

笔记：The shortest distance is calculated based on the specifiedFrom-Toline and is not affected by snapping.

The tolerance used whenFrom-To and Network Snappingis set toYes. Points of theFrom-To线将被扣为Network如果它们在这种公差范围内，则线路。