MRF2DIntersector
Note: The MRFCleaner transformers are available as an extra-cost package from Safe Software. Please contact sales@safe.com
or call 604-501-9985. This package includes all MRFCleaner transformers, available for Windows only (64-bit and 32-bit).
Computes intersections between all input features, breaking arcs and lines wherever an intersection occurs. A fuzzy intersection is also created from geometries which are within one of the tolerance distances, but do not actually touch or cross.
Output Ports
Each feature that is output through the Cleaned port will have a new attribute "mrf_clean_status" added to specify whether the feature was modified, created, or unchanged in the cleaning process. The possible values of this attribute are "Modified", "Created" and "Original".
If Intersection Action is set to Split Lines at Intersections, the input lines will be split at true intersection points into separate output lines. If it is set to Flag Intersections, then true intersection points will be output through the Flagged port as points, labels, or circles, depending on the Flag Type selected.
Parameters
Transformer
If selected, each group of features with the same values in the Group By attributes will be processed separately from other groups.
Process At End (Blocking): This is the default behavior. Processing will only occur in this transformer once all input is present.
Process When Group Changes (Advanced): This transformer will process input groups in order. Changes of the value of the Group By parameter on the input stream will trigger processing on the currently accumulating group. This may improve overall speed (particularly with multiple, equally-sized groups), but could cause undesired behavior if input groups are not truly ordered.
There are two typical reasons for using Process When Group Changes (Advanced) . The first is incoming data that is intended to be processed in groups (and is already so ordered). In this case, the structure dictates Group By usage - not performance considerations.
The second possible reason is potential performance gains.
Performance gains are most likely when the data is already sorted (or read using a SQL ORDER BY statement) since less work is required of FME. If the data needs ordering, it can be sorted in the workspace (though the added processing overhead may negate any gains).
Sorting becomes more difficult according to the number of data streams. Multiple streams of data could be almost impossible to sort into the correct order, since all features matching a Group By value need to arrive before any features (of any feature type or dataset) belonging to the next group. In this case, using Group By with Process At End (Blocking) may be the equivalent and simpler approach.
Note: Multiple feature types and features from multiple datasets will not generally naturally occur in the correct order.
As with many scenarios, testing different approaches in your workspace with your data is the only definitive way to identify performance gains.
Parameters
Cleaning tolerance is used as the default tolerance unless the Feature Tolerance Attribute is specified and valid. The minimum tolerance allowed is 0.0.
The number of layers used in cleaning the data is determined by the number of different tolerance values of input features. Features that have the same tolerances are processed as being on the same layer.
If set to Split Lines at Intersections, intersections are computed between all input features, breaking arcs and lines wherever an intersection occurs. If set to Flag Intersections, the Flag Type and Flag Size parameters are enabled.
If set to Yes, a fuzzy intersection is also created from geometries which are within one of the tolerance distances, but do not actually touch or cross.
This parameter sets the flag type for true intersection points as a point, label or circle, if Intersection Action is set to Flag Intersections.
Usage Notes
This transformer performs the same operation as the MRF2DCleaner no options selected except Compute True Intersections and/or Compute Fuzzy Intersections. See the MRF2DCleaner for more details.1 Note that the circle/label flagging is an added option in this transformer.
FME Licensing Level
The MRFCleaner transformers are available as an extra-cost package from Safe Software. Please contact sales@safe.com or call 604-501-9985.
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.
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