Standard deviation radius of gyration (Area and edge metric)
lsm_l_gyrate_sd(landscape, directions = 8, cell_center = FALSE)tibble
Raster* Layer, Stack, Brick, SpatRaster (terra), stars, or a list of rasterLayers.
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.
$$GYRATE_{SD} = sd(GYRATE[patch_{ij}])$$ where \(GYRATE[patch_{ij}]\) equals the radius of gyration of each patch.
GYRATE_SD is an 'Area and edge metric'. The metric summarises the landscape as the standard deviation of the radius of gyration of all patches in the landscape. GYRATE measures the distance from each cell to the patch centroid and is based on cell center-to-cell center distances. The metrics 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.
Meters
GYRATE_SD >= 0
Equals GYRATE_SD = 0 if the radius of gyration is identical for all patches. Increases, without limit, as the variation of the radius of gyration 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/
Keitt, T. H., Urban, D. L., & Milne, B. T. 1997. Detecting critical scales in fragmented landscapes. Conservation ecology, 1(1).
lsm_p_gyrate,
cv,
lsm_c_gyrate_mn,
lsm_c_gyrate_sd,
lsm_c_gyrate_cv,
lsm_l_gyrate_mn,
lsm_l_gyrate_cv