Computes and assigns the cost of the shortest path from a source object to each connected object as the Z-values or measure values of the input features.
Input Line features must be a topologically noded network with features connecting at line ends only. That is, all features must be split at junctions.
There can only be one Source input for each group.
All lines that are connected to the Source input port are output through the Connected port.
The lines that are not connected to the Source input port will be output through the Disconnected port. If Output Optimal Cost As parameter is set to Z-Values, the dimension of the disconnected lines is set to 2D. Otherwise, disconnected lines are untouched.
There can only be one Source input for each group. All other inputs and non-linear features are output through the Invalid port.
Choose the attributes to group by.
Note: How parallel processing works with FME: see About Parallel Processing for detailed information.
This parameter determines whether or not the transformer should perform the work across parallel processes. If it is enabled, a process will be launched for each group specified by the Group By parameter.
Parallel Processing Levels
For example, on a quad-core machine, minimal parallelism will result in two simultaneous FME processes. Extreme parallelism on an 8-core machine would result in 16 simultaneous processes.
You can experiment with this feature and view the information in the Windows Task Manager and the Workbench Log window.
Yes: This transformer will process input groups in order. Changes on the value of the Group By parameter on the input stream will trigger batch processing on the currently accumulating group. This will improve overall speed if groups are large/complex, but could cause undesired behavior if input groups are not truly ordered.
No: This is the default behavior. Processing will only occur in this transformer once all input is present.
If Weight Type is set to By Length (Forward Only) or By One Attribute, then the weight of each input line is set to the length of the line or the attribute value specified in the Forward Weight Attribute. In this case, the algorithm will only consider the original orientation of the lines when computing the cost of the shortest path.
If Weight Type is set to By Length or By Two Attributes, then the shortest path algorithm will consider both directions of the input lines. If Weight Type is set to By Two Attributes, the original orientation of the input line has the weight specified in the Forward Weight Attribute and the reversed orientation of the input line has the weight specified in the Reverse Weight Attribute. If Weight Type is set to By Length, the weight of both the original orientation and the reversed orientation of the input line is set to the length of the line.
Only linear features with non-negative weight attribute values are allowed if the Weight Type is set to By One Attribute or By Two Attributes. If a feature does not have the attribute specified in the Forward Weight Attribute or the Reverse Weight Attribute, a zero weight is used for the line.
If this parameter is set to Z-Values, then the optimal cost for each connected node is set as the Z-value of the node. Otherwise, the optimal cost is set as the measure value of the node with the measure name specified in Measure Name.
If you leave the Measure Name empty, the default measure name will be used.
If this parameter is set to Yes, the transformer snaps the source points to the closest end points of the network lines.
The source points are only snapped to the network lines if they are within the tolerance specified in Snapping Tolerance.
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.
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Tags Keywords: topology