FME Transformers: 2024.2
Categories and Related Transformers
Related Transformers
CoordinateExtractor
Counter
GeometryExtractor
GeometryPartCounter
HoleCounter
Extracts a feature’s total number of vertices, storing the result in an attribute.
Typical Uses
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Performing geometric calculations or manipulations
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Performing data quality checks
How does it work?
The VertexCounter receives any geometry type, and extracts each feature’s vertex count into an attribute.
Rasters, including digital elevation models, will receive a vertex count of their bounding box. Point clouds will receive a count of their total points.
Multi- and aggregate geometries will receive the sum of all vertices in all parts of the feature.
Examples
Example: Counting vertices on a line feature
In this example, we have a set of polylines representing rapid transit routes. We want to know how many vertices each feature has.
Note that the feature’s properties include a Number of Vertices value, but this is not readily accessible in the same way an attribute is.
The features are routed into a VertexCounter.
In the parameters dialog, the default Output Attribute Name for Vertex Count is kept.
The output features have a new attribute, _vertexcount, containing the count value.
Configuration
Input Ports
Input
This transformer accepts any feature.
Output Ports
Output
Features with their total number of vertices stored in the specified attribute.
Parameters
Output Attribute Name
|
Vertex Count |
Name the attribute to contain the number of vertices. The default value is _vertexcount. |
Editing Transformer Parameters
Transformer parameters can be set by directly entering values, using expressions, or referencing other elements in the workspace such as attribute values or user parameters. Various editors and context menus are available to assist. To see what is available, click 
beside the applicable parameter.
How to Set Parameter Values
Defining Values
There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters.
Using the Text Editor
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.
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.
Conditional Values
Set values depending on one or more test conditions that either pass or fail.
Parameter Condition Definition Dialog
Content
Expressions and strings can include a number of functions, characters, parameters, and more.
When setting values - whether entered directly in a parameter or constructed using one of the editors - strings and expressions containing String, Math, Date/Time or FME Feature Functions will have those functions evaluated. Therefore, the names of these functions (in the form @<function_name>) should not be used as literal string values.
Content Types
| These functions manipulate and format strings. | |
|
Special Characters |
A set of control characters is available in the Text Editor. |
| Math functions are available in both editors. | |
| Date/Time Functions | Date and time functions are available in the Text Editor. |
| These operators are available in the Arithmetic Editor. | |
| These return primarily feature-specific values. | |
| FME and workspace-specific parameters may be used. | |
| Creating and Modifying User Parameters | Create your own editable parameters. |
Dialog Options - Tables
Table Tools
Transformers with table-style parameters have additional tools for populating and manipulating values.
|
Row Reordering
|
Enabled once you have clicked on a row item. Choices include:
|
|
Cut, Copy, and Paste
|
Enabled once you have clicked on a row item. Choices include:
Cut, copy, and paste may be used within a transformer, or between transformers. |
|
Filter
|
Start typing a string, and the matrix will only display rows matching those characters. Searches all columns. This only affects the display of attributes within the transformer - it does not alter which attributes are output. |
|
Import
|
Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers. |
|
Reset/Refresh
|
Generally resets the table to its initial state, and may provide additional options to remove invalid entries. Behavior varies between transformers. |
Note: Not all tools are available in all transformers.
For more information, see Transformer Parameter Menu Options.
Reference
|
Processing Behavior |
|
|
Feature Holding |
No |
| Dependencies | None |
| Aliases | CoordinateCounter |
| History |
FME Community
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Examples may contain information licensed under the Open Government Licence – Vancouver, Open Government Licence - British Columbia, and/or Open Government Licence – Canada.