Local drain direction map cut into a (smaller) sound local drain direction map
Result = lddmask(ldd, mask)
The cell values on mask are interpreted as boolean values, where 1 is TRUE and 0 is FALSE. The part of the local drain direction map ldd which you want to cut out must totally be filled with 1 (TRUE) values on mask.
Each cell with a mask value 0 (FALSE) is assigned a missing value on Result. Each cell with a mask value 1 (TRUE) is assigned a value which corresponds with the value on ldd, except cells with a mask value 1 that have a local drain direction on ldd towards a cell with a 0 (FALSE) on mask. These last named cells are outflow cells on the edge of the new ldd, these are assigned a cell value 5, which is the ldd code for a pit.
A cell with a missing value on mask is interpreted as a mask value 0 (FALSE) and handled in that way. In addition, a cell with a missing value on ldd is assigned a missing value on Result.
This operation belongs to the group of Missing value creation
- • pcrcalcbindingResult = Result.map;Ldd = Ldd.map;Mask = Mask.map;initialreport Result = lddmask(Ldd,Mask);• pythonLdd = readmap(“Ldd.map”)Mask = readmap(“Mask.map”)Result = lddmask(Ldd,Mask)