Radius of Gyration (Area and edge metric)
lsm_p_gyrate(landscape, directions = 8, cell_center = FALSE)tibble
A categorical raster object: SpatRaster; Raster* Layer, Stack, Brick; stars or a list of SpatRasters.
The number of directions in which patches should be connected: 4 (rook's case) or 8 (queen's case).
If true, the coordinates of the centroid are forced to be a cell center within the patch.
$$GYRATE = \sum \limits_{r = 1}^{z} \frac{h_{ijr}} {z}$$ where \(h_{ijr}\) is the distance from each cell to the centroid of the patch and \(z\) is the number of cells.
GYRATE is an 'Area and edge metric'. The distance from each cell to the patch centroid is based on cell center to centroid distances. The metric characterises both the patch area and compactness.
If cell_center = TRUE some patches might have several possible cell-center
centroids. In this case, the gyrate index is based on the mean distance of all
cells to all possible cell-center centroids.
Because the metric is based on distances or areas please make sure your data
is valid using check_landscape.
Meters
GYRATE >= 0
Approaches GYRATE = 0 if patch is a single cell. Increases, without limit, when only one patch is present.
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
Keitt, T. H., Urban, D. L., & Milne, B. T. 1997. Detecting critical scales in fragmented landscapes. Conservation ecology, 1(1).
lsm_c_gyrate_mn,
lsm_c_gyrate_sd,
lsm_c_gyrate_cv,
lsm_l_gyrate_mn,
lsm_l_gyrate_sd,
lsm_l_gyrate_cv
landscape <- terra::rast(landscapemetrics::landscape)
lsm_p_gyrate(landscape)
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