VertexRemover

Removes specific vertices from a feature’s geometry.

Typical Uses

Isolating vertices
Removing portions of vector geometry

How does it work?

The VertexRemover receives features with vector geometry and removes specific vertices (coordinates) from them.

Specified vertices may be either removed or kept. If they are kept, all other vertices are removed.

Vertices are identified by their Coordinate Index position, starting at zero (0), and a Number to Keep/Remove, which is extended from the given index position. For example -

If keeping coordinates, if the Coordinate Index is 0 and the Number to Keep/Remove is 15, the first 15 vertices will remain and the rest will be removed.
If removing coordinates, the first 15 vertices would be removed.

Vertices can also be identified by their position relative to the end of the geometry, where -1 is the last vertex, -2 is second-to-last, and so on. The Number to Keep/Remove will still be extended forwards (towards the end of the feature). For example -

If keeping coordinates, if the Coordinate Index is -22 and the Number to Keep/Remove is 22, the last 22 vertices will remain and the rest will be removed.
If removing coordinates, the last 22 vertices will be removed.

An attribute _num_removed is added to the features, indicating the number of vertices removed.

Multi- or aggregate geometries, 3D geometries, rasters, point clouds, and non-spatial features will be rejected.

Areas with holes (donuts) will not produce useful results.

Examples

Configuration

Input Ports

Output Ports

Parameters

General

Keep or Remove Coordinates

Select how coordinates are identified for removal:

Remove: Vertices described by the Coordinate Index and Number to Keep/Remove parameters will be deleted.
Keep: Vertices described by the Coordinate Index and Number to Keep/Remove parameters will be kept, and all other coordinates deleted.

Coordinate Index

Specify the index position of the first vertex of interest.

The index starts at zero (0), indicating the first vertex.

Negative integers are used to indicate position relative to the last vertex, where -1 is last, -2 is second-to-last, and so on.

The index value may be entered directly or provided via an attribute, expression, user parameter, or conditional value.

Number to Keep/Remove

Specify the number of vertices of interest, moving towards the end of the feature from the position specified in Coordinate Index.

The value may be entered directly or provided via an attribute, expression, user parameter, or conditional value.

Editing Transformer Parameters

Using a set of menu options, transformer parameters can be assigned by referencing other elements in the workspace. More advanced functions, such as an advanced editor and an arithmetic editor, are also available in some transformers. To access a menu of these options, click beside the applicable parameter. For more information, see Transformer Parameter Menu Options.

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. There are a number of tools and shortcuts that can assist in constructing values, generally available from the drop-down context menu adjacent to the value field.

How to Set Parameter Values

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.

Text Editor

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.

Arithmetic Editor

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

String Functions	These functions manipulate and format strings.
Special Characters	A set of control characters is available in the Text Editor.
Math Functions	Math functions are available in both editors.
Date/Time Functions	Date and time functions are available in the Text Editor.
Math Operators	These operators are available in the Arithmetic Editor.
FME Feature Functions	These return primarily feature-specific values.
FME Parameters	FME and workspace-specific parameters may be used.
Creating and Modifying User Parameters	Create your own editable parameters.

Dialog Options - Tables

Transformers with table-style parameters have additional tools for populating and manipulating values.

Table Tools

Row Reordering

Enabled once you have clicked on a row item. Choices include:

Add a row
Remove a row
Move current row up one
Move current row down one
Move current row to top
Move current row to bottom

Cut, Copy, and Paste

Enabled once you have clicked on a row item. Choices include:

Cut a row - delete and copy to clipboard
Copy a row to the clipboard
Paste a row from the clipboard

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.

Reference

Processing Behavior	Feature-Based
Feature Holding	No
Dependencies	None
Aliases	CoordinateRemover
History

FME Community

The FME Community is the place for demos, how-tos, articles, FAQs, and more. Get answers to your questions, learn from other users, and suggest, vote, and comment on new features.

Search for all results about the VertexRemover on the FME Community.

Examples may contain information licensed under the Open Government Licence – Vancouver and/or the Open Government Licence – Canada.