lidR (version 1.2.1)

rumple_index: Rumple index of roughness

Description

Computes the roughness of a surface as the ratio between the area of a surface and its projected area on the ground. For each type of input the function makes a Delaunay triangulation of the points and computes the ratio between the area of the triangles and the area or the convexhull (i.e. the projected area of the triangles on the X-Y plane).

Usage

rumple_index(x, y = NULL, z = NULL, ...)

Arguments

x

A 'RasterLayer' or a 'lasmetrics' object, or a vector of x point coordinates.

y

numeric. If x is a vector of coordinates: the associated y coordinates.

z

numeric. If x is a vector of coordinates: the associated z coordinates.

...

unused

Value

numeric. The computed Rumple index.

Examples

# NOT RUN {
x = runif(20, 0, 100)
y = runif(20, 0, 100)

# Perfectly flat surface, rumple_index = 1
z = rep(10, 20)
rumple_index(x, y, z)

# Rough surface, rumple_index > 1
z = runif(20, 0, 10)
rumple_index(x, y, z)

# Rougher surface, rumple_index increases
z = runif(20, 0, 50)
rumple_index(x, y, z)

# Measure of roughness is scale dependent
rumple_index(x, y, z)
rumple_index(x/10, y/10, z)

# Use with a canopy height model
LASfile <- system.file("extdata", "Megaplot.laz", package="lidR")
las = readLAS(LASfile)
chm = las %>% grid_canopy
rumple_index(chm)
# }