The Flow direction operation can be directly executed by typing one of the following expressions on the command line of the Main window:
|
OUTMAP |
= |
MapFlowDirection(InputMapName) |
|
OUTMAP |
= |
MapFlowDirection(InputMapName, slope | height) |
where:
|
OUTMAP |
is the name of the output raster map. |
|
MapFlowDirection |
is the command to start the Flow direction operation. |
|
InputMapName |
is the name of the input raster map (value domain); the input raster map is expected to be a sink-free Digital Elevation Model (DEM). |
|
slope | height |
is an optional parameter to indicate how flow direction should be calculated. |
|
slope |
calculate flow direction as the run off to a neighbour pixel according to steepest downhill slope. |
|
height |
calculate flow direction as the run off to the neighbour pixel which has the lowest height (smallest value). |
When the definition symbol = is used, a dependent output map is created; when the assignment symbol := is used, the dependency link is immediately broken after the output map has been calculated.
The output map will always use system domain FlowDirection.
See also: