mArea: Area of objects
In EhrmannS/rasterTools: Obtain and process earth observation data

Description Usage Arguments Value See Also Examples

Calculate the area of objects in a raster

1	mArea(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"`, `"class"` and `"landscape"`.
`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 number of raster cells.
`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 = "landscape" the area of the overall raster, for scale = "class" the total area of each unique value (class), for scale = "patch" the area of distinct objects per distinct values (i.e. the area of patches per class).

Other generic metrics: mAdjacency, mNumber, mPerimeter, mValues

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

# the area ...
# ... per landcover type
mArea(obj = cat, scale = "class")

# ... of patches per landcover type
mArea(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)) %>%
  mArea(scale = "patch", layer = "values_binarised")

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