Perimeter-Area ratio (Shape metric)
lsm_p_para(landscape, directions = 8)tibble
Raster* Layer, Stack, Brick, stack, or a list of rasterLayers.
The number of directions in which patches should be connected: 4 (rook's case) or 8 (queen's case).
$$PARA = \frac{p_{ij}} {a_{ij}}$$ where \(p_{ij}\) is the perimeter in meters and \(a_{ij}\) is the area in square meters.
PARA is a 'Shape metric'. It describes the patch complexity in a straightforward way. However, because it is not standarised to a certain shape (e.g. a square), it is not scale independent, meaning that increasing the patch size while not changing the patch form will change the ratio.
None
PARA > 0
Increases, without limit, as the shape complexity increases.
McGarigal, K., SA Cushman, and E Ene. 2012. FRAGSTATS v4: Spatial Pattern Analysis Program for Categorical and Continuous Maps. Computer software program produced by the authors at the University of Massachusetts, Amherst. Available at the following web site: https://www.umass.edu/landeco/
lsm_p_area,
lsm_p_perim,
lsm_c_para_mn,
lsm_c_para_sd,
lsm_c_para_cv,
lsm_l_para_mn,
lsm_l_para_sd,
lsm_l_para_cv