lsm_p_gyrate() R function from [landscapemetrics]

GYRATE (patch level)

Radius of Gyration (Area and edge metric)


lsm_p_gyrate(landscape, directions = 8, cell_center = FALSE)

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).
cell_center: If true, the coordinates of the centroid are forced to be a cell center within the patch.

Returns

tibble

Details

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.

Units

Meters

Range

GYRATE >= 0

Behaviour

Approaches GYRATE = 0 if patch is a single cell. Increases, without limit, when only one patch is present.

Examples


landscape <- terra::rast(landscapemetrics::landscape)
lsm_p_gyrate(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

Keitt, T. H., Urban, D. L., & Milne, B. T. 1997. Detecting critical scales in fragmented landscapes. Conservation ecology, 1(1).

lsm_p_gyrate function