angularity {doolkit}

angularity

Description

Compute the angularity (delta slope).

Usage

angularity(mesh, ratio = FALSE)

Arguments

mesh

object of class mesh3d

ratio

logical, if false standard angularity will be computed (default), if true a relative angularity ratio will be computed (see below)

Value

If ratio = FALSE, a numeric vector of angularity values i.e. delta slope of each polygon compared to their adjacent polygons, for all the polygons of the mesh. If ratio = TRUE, a numeric vector of angularity ratio values. Ratio is computed by dividing polygon slope by 90, replacing vertex elevation by the average ratio of faces adjacent to the vertex, then dividing the slope of polygons from this new mesh by 90. Although it is a non-standard variable, it was implemented because it better discriminates sharp edges than basic angularity. Warning: both options can take up a significant amount of time for large meshes.

References

Ungar and Williamson (2000)

Examples

delta_slope <- angularity(dkmodel$complex, ratio = FALSE)
summary(delta_slope)
#angularity ratio:
delta_slope_ratio <- angularity(dkmodel$complex, ratio = TRUE)
summary(delta_slope_ratio)

#render on a map:
dkmap(dkmodel$complex, delta_slope, col = "slope",
legend.lab = "Angularity (°)")
#angularity ratio:
dkmap(dkmodel$complex, delta_slope_ratio, col = "slope",
legend.lab = "Angularity ratio")