Mean of related circumscribing circle (Shape 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
$$CIRCLE_{MN} = mean(CIRCLE[patch_{ij}])$$ where \(CIRCLE[patch_{ij}]\) is the related circumscribing circle of each patch.
CIRCLE_MN is a 'Shape metric' and summarises the landscape as the mean of the related circumscribing circle of all patches in the landscape. CIRCLE describes the ratio between the patch area and the smallest circumscribing circle of the patch and characterises the compactness of the patch.
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
Baker, W. L., and Y. Cai. 1992. The r.le programs for multiscale analysis of landscape structure using the GRASS geographical information system. Landscape Ecology 7: 291-302.
Based on C++ code from Project Nayuki (https://www.nayuki.io/page/smallest-enclosing-circle).