mPerimeter: Edge length
In EhrmannS/rasterTools: Obtain and process earth observation data

Description Usage Arguments Value See Also Examples

Calculate the length of edges/boundaries between objects in a spatial raster.

1	mPerimeter(obj, scale = "patch", unit = "cells", layer = NULL)

`obj`	[`Raster*(1)`] The object to measure.
`scale`	[`character(1)`] scale at which the area of objects should be calculated; possible values are `"patch"` and `"class"`.
`unit`	[`character(1)`] the unit the output should have. With `"map"` the result will be in the respective map unit and with `"cells"` (default) it will be the multiple of the raster cell dimension.
`layer`	[`character(1)`] in case `obj` has several layers, specify here the layer for which the area of objects shall be calculated (by default, the first layer).

For scale = "class" the edge length of each unique value (class) in the raster, for scale = "patch" the edge length of distinct objects per distinct values (i.e. the area of patches per class).

Other generic metrics: mAdjacency, mArea, mNumber, mValues

cat <- rtRasters$categorical
bin <- rBinarise(rtRasters$continuous, thresh = 40)

# the perimeter ...
# ... per landcover type
mPerimeter(obj = cat, scale = "class")

# ... of patches per landcover typ
mPerimeter(obj = cat, scale = "patch")

# ...  of certain values; from a binary raster, patches are 
# automatically determined
require(magrittr)
rBinarise(obj = cat, match = c(41, 44, 47)) %>%
  mPerimeter(scale = "patch", layer = "values_binarised")

mPerimeter(obj = bin, scale = "class")