Validation

This chapter compares our output with that of gdaldem.

We test with the same elevation model as that in the Usage page, and also include an upside down version of it, to ensure that the algorithms are robust to different axes conventions.

@info Geomorphometry.cellsize(dem)  # default negative y spacing
@info Geomorphometry.cellsize(ndem)  # reversed y spacing

┌ Error: Unknown CRS type, please report this issue for the given crs/file
└ @ GeoArrays ~/.julia/packages/GeoArrays/X63Mm/src/geointerface.jl:11
[ Info: (5.0, -5.0)
┌ Error: Unknown CRS type, please report this issue for the given crs/file
└ @ GeoArrays ~/.julia/packages/GeoArrays/X63Mm/src/geointerface.jl:11
[ Info: (5.0, 5.0)

Hillshade

heatmap(hillshade(dem))

Multihillshade

heatmap(multihillshade(dem))

Slope

Horn

heatmap(slope(dem, method=Horn()))

ZevenbergenThorne

heatmap(slope(dem, method=ZevenbergenThorne()))

Aspect

Horn

heatmap(aspect(dem, method=Horn()))

ZevenbergenThorne

heatmap(aspect(dem, method=ZevenbergenThorne()))