| outlet {topmodel} | R Documentation |
Convenience function to extract a pixel and its neighbourhood from matrices representing, e.g. to query raster maps.
outlet(map,out,radius = 2)
map |
matrix |
out |
Center of the matrix to be extracted |
radius |
Radius of the matrix to be extracted |
The function can be used to find a catchment outlet using a drainage area map generated by atb, when the coordinates are approximately known (for instance from the location of a discharge station). These coordinates can then be used by subcatch. However, note that atb uses a multiple direction flow algorithm, while subcatch uses single flow. Therefore, the drainage area for a pixel calculated by atb is likely to differ from the catchment area identified by subcatch.
Square matrix of size (radius * 2 + 1)
Wouter Buytaert, Imperial College London
See http://wiki.r-project.org/rwiki/doku.php?id=guides:tutorials:hydrological_data_analysis for examples.