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CommonLocalReprojector

Reprojects a set of features to a local coordinate system with units of meters centered on the bounding box of the features.

This transformer is useful if you need a number of features reprojected into the same local coordinate system.

Parameters

Transformer

ClosedGroup By

If attributes are not specified, all features will be reprojected to the same local coordinate system. If attributes are specified, each group of features will be reprojected to a local coordinate system centered on that group.

ClosedParallel Processing Level

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.

ClosedInput is Ordered by Group

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.

Parameters

ClosedProjection Type

Choose the local projection from the drop-down list based on whether preservation of distances or areas is more important. Choices are:

  • AZMED (Lambert Azimuthal Equidistant)
  • AZMEA (Lambert Azimuthal Equal Area)
ClosedVertical Handling

This parameter determines how Z values will be handled:

  • Ignore heights and leave them unchanged: Z values will not affect the reprojection and will not be changed.
  • Heights are relative to the ellipsoid or geocentric: Z values will be treated as ellipsoid heights with the same units as the horizontal units (or meters, for geographic coordinate systems). If the source coordinate system is geocentric, coordinates will be converted to geographic+ellipsoid height before being processed.

Note: Note that rasters can only be reprojected in 2D (that is, with Ignore heights and leave them unchanged).

Usage Notes

Local coordinate systems have the following limitation:

  • Height is not considered so areas or distances are best preserved for geometry at an ellipsoid height of 0 meters. Despite height not affecting the coordinate system that will be generated, Z values may undergo a unit shift or geocentric to ellipsoid height conversion if a Vertical Handling mode of Heights are relative to the ellipsoid or geocentric is chosen.

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.

Transformer Categories

Coordinate Systems

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