SpikeRemover

Cleans up feature geometries by removing spikes.

The transformer looks at every pair of line segments made up of three consecutive distinct points. If the angle (in degrees) between two line segments is less than or equal to the specified maximum angle, then the middle point is a spike and is removed.

If the geometry of a feature is a path, the transformer removes spikes between consecutive path segments as well. For a polygon or donut, if the start/end point is a spike, then it is also removed. The end result is still a polygon/donut. Any polygons, donuts, paths or lines that are part of a collection of geometry will also be processed.

The transformer will also remove any consecutive duplicate points.

The transformer is not effective when the line contains many deviations other than spikes. In such cases, it is recommended to first clean up the features using the Generalizer transformer with Douglas-Peucker algorithm.

Example

Configuration

Output Ports

Parameters

General

Maximum Spike Angle	If the angle (in degrees) between two line segments is less than or equal to this parameter, then the middle point is a spike and is removed. The value must be between 0 and 180 degrees.
Maximum Spike Length	If the Maximum Spike Length is specified, then the transformer will skip line segments longer than this length; otherwise, all line segments are considered.
Dimension	3D: Z coordinates of line segments will be used when finding spike angle and length. 2D: Z coordinates of line segments will be ignored when finding spike angle and length.
Remove Spikes Iteratively	No – The Removed features will have the following details about the spike added as attributes: _spike_angle, _spike_length1, and _spike_length2. Yes – The transformer will ensure that no spikes are left behind (but it will not return the attributes _spike_angle, _spike_length1, and _spike_length2).

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.

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

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:

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.

For more information, see Transformer Parameter Menu Options.

FME Community

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