LineOnLineOverlayer

The Group By parameter specifies a series of attributes that must match on the features before they are considered for overlaying. This can be used to ensure that the overlay occurs only on certain groups of features. Click the browse button to select from a list of attributes.

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

Parameter	Number of Processes
No Parallelism	1
Minimal	coresThe processor, or CPU, is the physical part of the computer that performs mathematical calculations. It is the most important part of a computer system. Traditional processors have only one core on the processor, meaning that at any given time, only one set of calculations is being performed. If a processor is dual-core, this means the single chip contains hardware for two processors, now called cores to distinguish them from the single chip, running simultaneously, side by side. (Source: http://www.ehow.com/facts_5730257_computer-core-processors_.html) / 2
Moderate	exact number of cores
Aggressive	cores x 1.5
Extreme	cores x 2

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.

No: This is the default behavior. Processing will only occur in this transformer once all input is present.

By Group: 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.

The Overlap Count Attribute holds the number of line features that intersected the resultant feature.

No: All collinear segments are reduced to one representative segment.

Yes: All collinear segments are output.

Full: All operations are logged.

Limited: Underlying intersection operations are not logged.

Specifies how attributes should be accumulated. If Drop Attributes is selected, all incoming attributes are removed from the features. Merge Attributes merges all attributes from overlapping segments. Get Attributes From One Representative Feature takes all attributes from one representative feature.

When Separate Collinear Segments is Yes, and Accumulation Mode is Merge Attributes, this value prefixes all incoming attributes on collinear segments. It does not affect node output.

Allows you to specify a List Name.

If specified, a list of the attributes of each line that overlapped an output segment is made. This allows later inspection of overlapping segment attributes.

Note: List attributes are not accessible from the output schema in Workbench unless they are first processed using a transformer that operates on them, such as ListExploder or ListConcatenator. All list attribute transformers are displayed in the Contents pane of the Transformer Help under Lists. Alternatively, AttributeExposer can be used.