Breaks input features into points, lines, or areas. Chopped features contain the same set of vertices as input features.
This is useful when outputting to a format that has limitations on the number of coordinates in each feature. It can also be used to crudely simplify complex objects.
All new features have the same attributes as the original feature had and are output via the Output port. The optional chopping indicator attribute can be used to distinguish output features which were chopped from output features which were not.
Input Ports
Input
Lines and areas will be processed.
Output Ports
Output
Chopped and untouched features are output to this port.
<Rejected>
Invalid features will be routed to the <Rejected> port, as well as features that receive unexpected parameter values (non-numeric) for length or number of vertices.
Rejected features will have an fme_rejection_code attribute with one of the following values:
INVALID_PARAMETER_NUM_VERTICES
INVALID_PARAMETER_LENGTH
INVALID_GEOMETRY_TYPE
Rejected Feature Handling: can be set to either terminate the translation or continue running when it encounters a rejected feature. This setting is available both as a default FME option and as a workspace parameter.
Parameters
General
Maximum Vertices
Each Output feature will have up to the specified number of vertices. For example, if an input line consists of 4 vertices, and a Maximum Vertices of 3 is specified, two Output lines would be output: one with 3 vertices and one with 2 vertices.
If this parameter is less than 4, input area features are converted to linear features. If it is set to 1, all input features are broken up into point features.
Remnant Attribute
If the feature is a line and the final piece of the Output line feature does not have the same number of vertices as the other pieces, this attribute (if specified) will be added with a value of “yes”, otherwise this attribute will have the value “no”.
Approximate Length
Each Output line feature will be a line feature whose length is close to the value specified in this parameter. Whenever two input vertices may represent the endpoint of an Output line feature, FME chooses the one that results in a length closer to the value of Approximate Length.
For example, if a horizontal line consists of two segments of length 0.8, and you specify 1 for Approximate Length, then the output is expected to be two line features each containing two vertices, and each a length of 0.8.
For area features, the Approximate Length determines the approximate height and width of chopped areas. If vertex spacing along the line is greater than the Approximate Length, larger areas will result. By default, Add Interior Points (Areas Only) is set to Yes, meaning that new vertices may be introduced to the interior of areas.
Add Interior Vertices (Areas Only)
Yes: New vertices will be introduced while chopping up an input area feature whenever needed. These vertices are guaranteed to fall inside the input area.
No: No new vertices will be introduced. This means if an input area cannot be chopped up without new vertices within the confines of Approximate Length, then it will be output unmodified. It is also possible that many of the pieces produced by chopping will be larger than the Approximate Length, since no smaller pieces can be generated without introducing interior vertices.
Chopped Indicator Attribute
This attribute (if specified) will be added with a value of “yes” to any output features which were chopped, and a value of “no” to any output features which were untouched by the transformer.
Usage Notes
Input arcs are stroked prior to chopping. If the chopping operation does not modify a stroked arc, the arc is unstroked and will be output untouched.
Area features are chopped in such a way as to preserve the original area of the feature. That is, the original area feature is cut into smaller areas, which if dissolved together, would match the original area. New vertices may be introduced into the area feature as it is chopped.
Example
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.
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. | |
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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
Transformers with table-style parameters have additional tools for populating and manipulating values.
Table Tools
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Row Reordering
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Enabled once you have clicked on a row item. Choices include:
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Cut, Copy, and Paste
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Enabled once you have clicked on a row item. Choices include:
Cut, copy, and paste may be used within a transformer, or between transformers. |
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Filter
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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. |
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Import
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Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers. |
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Reset/Refresh
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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.
FME Community
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