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DEMDistanceCalculator

Calculates the distance between a number of input vector lines and the elevation values of a reference DEM raster, and outputs a new DEM raster per input line.

The data contained in the resulting DEM consists of the 3D distance between the line being considered and the corresponding point on the reference DEM.

Input Ports

ClosedRefDem

A reference DEM raster. Only the first raster feature received for each Group By grouping will be used.

ClosedLine

3D line features.

Output Ports

Closed3DDist

Raster DEMs representing the 3D distance between a line and the corresponding point on the reference DEM.

Closed<Rejected>

Any input features entering the Line port that are not 3D lines will be rejected with the fme_rejection_code attribute set to INVALID_VECTOR_GEOMETRY_TYPE.

Any input features entering the RefDem port that are not valid DEM rasters will be rejected with the fme_rejection_code attribute set to INVALID_REF_RASTER_GEOMETRY.

If more than one DEM raster is received for a Group By grouping, the extra rasters will be rejected with the fme_rejection_code attribute set to EXTRA_REF_RASTER_FEATURE.

Parameters

ClosedGroup By

Use this parameter to organize lines into groups, with each group of lines having its own reference DEM.

ClosedParallel Processing

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 Ordered

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.

Usage Notes

This transformer supports raster band and palette selection. The RasterSelector can be used to modify selection.

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

3D

Calculated Values

Rasters

Spatial Analysis

FME Licensing Level

FME Professional edition and above

 

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Tags Keywords: raster band palette vector distance DEM