RasterCellValueCalculator

Unselected bands are appended to the output raster, unchanged. The unselected bands of raster A are appended first, followed by the unselected bands of raster B.

To perform a calculation on more than one pair of rasters, a set of Group By attributes must be specified. Each group must contain one A raster and one B raster.

Group By attributes are always added to the output feature.

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.

This parameter sets the operation that will be performed:

+	add
-	subtract
*	multiply
/	divide
Minimum Maximum Average	takes the minimum, maximum or average of A and B

For example, if you select the plus sign (+), the two input rasters A and B will be added together (and therefore, the output raster will be A+B).

If Preserve Interpretation is set to Yes, each output band will have the same interpretation as its input bands when the input bands share the same interpretation. If the input bands have different interpretations, or Preserve Interpretation is set to No, the interpretation of each output band will be automatically determined.

Note that when converting between different data types, a Bounded Cast is used. As a result, when a calculated value does not fit in the destination interpretation, the corresponding destination value will either be set to the minimum or maximum value possible in the destination data type.

If Accumulate Attributes is set to Yes, then the attributes from the original features will be merged onto the output feature. Group By attributes are always added to the output feature.