Total area (Area and edge metric)

## Arguments

- landscape
A categorical raster object: SpatRaster; Raster* Layer, Stack, Brick; stars or a list of SpatRasters.

- directions
The number of directions in which patches should be connected: 4 (rook's case) or 8 (queen's case).

## Details

$$CA = sum(AREA[patch_{ij}])$$ where \(AREA[patch_{ij}]\) is the area of each patch in hectares.

TA is an 'Area and edge metric'. The total (class) area sums the area of all patches in the landscape. It is the area of the observation area.

Because the metric is based on distances or areas please make sure your data
is valid using `check_landscape`

.

## References

McGarigal K., SA Cushman, and E Ene. 2023. FRAGSTATS v4: Spatial Pattern Analysis Program for Categorical Maps. Computer software program produced by the authors; available at the following web site: https://www.fragstats.org