Leftrightspatialcalculator.

在被派出之前Outputport, each候选人feature will have a list of its relative positions to each of the根据features attached to it. Each element of the list has two pieces of information:

• 英航“base_id”标识se
• 计算的相对“位置”

根据使用后删除功能。

任何根据feature that is not a line is output through this port. All null and aggregate候选人功能通过此端口输出。有效的部分将通过该部分输出Output端口，无效部分将输出<被拒绝>港口。

如果您按属性选择组，考生只是比较反对根据sthat have the same values in these attributes.

Process At End (Blocking): This is the default behavior. Processing will only occur in this transformer once all input is present.

Process When Group Changes (Advanced): This transformer will process input groups in order. Changes of the value of the Group By parameter on the input stream will trigger processing on the currently accumulating group. This may improve overall speed (particularly with multiple, equally-sized groups), but could cause undesired behavior if input groups are not truly ordered.

Considerations for Using通过...分组

使用两种典型的原因Process When Group Changes (Advanced). The first is incoming data that is intended to be processed in groups (and is already so ordered). In this case, the structure dictates Group By usage - not performance considerations.

The second possible reason is potential performance gains.

最有可能在已经对数据进行排序的（或使用A读取SQL ORDER BY声明）由于FME需要更少的工作。如果数据需求排序，则可以在工作区中排序（尽管添加的处理开销可能会否定任何增益）。

Sorting becomes more difficult according to the number of data streams. Multiple streams of data could be almost impossible to sort into the correct order, since all features matching a通过...分组value need to arrive before any features (of any feature type or dataset) belonging to the next group. In this case, using通过...分组和Process At End (Blocking)可能是等同和更简单的方法。

Note: ">不te:Multiple feature types and features from multiple datasets will not generally naturally occur in the correct order.

As with many scenarios, testing different approaches in your workspace with your data is the only definitive way to identify performance gains.

如果选择是（默认），则该算法将仅使用传递的核心考生instead of the whole geometry.

If you choose是的, the algorithm will compute only at the point on the根据line that is closest to the first or "center of mass" point.

Note: ">不te:对于某些情况而言，算法中的数学可能产生与人眼会主观预期的相反的结果。

If you choose不, the algorithm will use a "gravity" or "weighted" based method such that all segments are used; segments from the base line that are closer to the candidate will contribute a higher weight than the segments that are farther away. The weights are added for each of the base's segments and will produce left or right depending on the group consensus. This will usually produce a subjectively more visually appealing result.

Note: ">不te:可能存在一些边缘案例将返回不正确的结果。

定义是否仅提供单个基础，或者是否将提供多个基础。如果您首先选择基地，所有根据功能将首先进入变压器，在任何内容之前候选人features.

Choose the根据attribute whose value will be used to identify it in the list of relative positions attached to each output候选人.

指定将添加到所有输出上的列表属性的名称候选人features, and that will contain the relative positions.

使用文本编辑器

The Text Editor provides a convenient way to construct text strings (including regular expressions) from various data sources, such as attributes, parameters, and constants, where the result is used directly inside a parameter.

文本编辑器

Using the Arithmetic Editor

The Arithmetic Editor provides a convenient way to construct math expressions from various data sources, such as attributes, parameters, and feature functions, where the result is used directly inside a parameter.

算术编辑器

Conditional Values

根据通过或失败的一个或多个测试条件设置值。

参数条件定义对话框

内容

Expressions and strings can include a number of functions, characters, parameters, and more.

设置值 - 无论是否直接在参数中输入或使用其中一个编辑器和包含字符串的表达式都是构造的，都会评估这些函数的字符串和表达式。因此，这些函数的名称（以@ <function_name.>) should not be used as literal string values.

内容类型

字符串函数	These functions manipulate and format strings.
Special Characters	A set of control characters is available in the Text Editor.
数学函数	两个编辑器都有数学函数。
日期/时间函数	Date and time functions are available in the Text Editor.
Math Operators	These operators are available in the Arithmetic Editor.
FME功能功能	这些主要是特定于特征的值。
FME参数	可以使用FME和工作区的参数。
创建和修改用户参数	创建自己的可编辑参数。

不te:不t all tools are available in all transformers.