2DBoxReplacer
Replaces feature geometry with a 2D box defined by specified minimum and maximum x and y values.
Typical Uses
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Creating search envelopes
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Creating clip boundaries
How does it work?
The 2DBoxReplacer receives features of any kind and replaces their geometry with 2D boxes as specified in parameters.
The parameters describe rectangular geometry with minimum and maximum x and y values, representing the box's lower left and upper right corners, in the ground units of the feature’s coordinate system.
Values may be entered directly or provided via attributes, parameters, or expressions.
Examples
In this example, we have a point dataset of food cart vendors. We want to replace the points with boxes centered on the point locations.
Note that the features have a UTM coordinate system, with ground units in meters.
The features are routed into a 2DBoxReplacer.
In the parameters dialog, expressions are created to offset the corners by 50 meters from the point location.
The points have been replaced with boxes.
Usage Notes
Creating Boxes and Rectangles
Creating rectangular geometry is a common task. These transformers do so in a variety of ways.
Transformer |
Function |
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Creates one or more new features with box geometry of a specific size and position (when Geometry Object is Box). |
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Replaces an existing feature’s geometry with a box of a specific size and position. |
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Creates one rectangle that encompasses all features received. |
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Individually replaces the geometry of each feature with a rectangle that covers its extents. |
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Individually replaces the geometry of each raster feature with a rectangle that covers its extents (with various Extents Type options). |
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Extracts the coordinate values that describe an individual feature’s bounding box (or cube) and stores them as attributes. |
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Creates a series of regularly-spaced rectangles that span the extent of all features received (when Type of Grid to Create is Polygons). |
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Creates a series of regularly-spaced rectangles of a specific size and position (when Type of Grid to Create is Polygons). |
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Tiler and RasterTiler |
Do not create actual rectangles, but chop features into a series of rectangular tiles, specified in a similar fashion to the 2DGridAccumulator. |
Configuration
Input Ports
This transformer accepts any feature.
Output Ports
The dynamic <Rejected> port appears when a parameter is set to a non-literal value that might make processing impossible.
For example, if a numeric parameter such as Line Width, Count Start, or Decimal Places is set to an expression, attribute value, or user parameter, it is possible to pass in a non-numeric value that cannot be used. Decimal Places = Cat cannot be processed, so the feature will be output via this port.
Rejected features will have an fme_rejection_code attribute explaining the reason for rejection.
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
Min X Value |
Specify the minimum x value (lower left) of the box. |
Min Y Value |
Specify the minimum y value (lower left) of the box. |
Max X Value |
Specify the maximum x value (upper right) of the box. |
Max Y Value |
Specify the maximum y value (upper right) of the box. |
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.
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.
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
Transformers with table-style parameters have additional tools for populating and manipulating values.
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. |
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. |
Import
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Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers. |
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.
Reference
Processing Behavior |
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Feature Holding |
No |
Dependencies | None |
Aliases | |
History |
FME Community
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Examples may contain information licensed under the Open Government Licence – Vancouver and/or the Open Government Licence – Canada.