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CIRCLE_CV (Class level)

Source: R/lsm_c_circle_cv.R
lsm_c_circle_cv.Rd

Coefficient of variation of related circumscribing circle (Shape metric)

Usage

lsm_c_circle_cv(landscape, directions = 8)

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).

Value

tibble

Details

$$CIRCLE_{CV} = cv(CIRCLE[patch_{ij}])$$ where \(CIRCLE[patch_{ij}]\) is the related circumscribing circle of each patch.

CIRCLE_CV is a 'Shape metric' and summarises each class as the Coefficient of variation of the related circumscribing circle of all patches belonging to class i. CIRCLE describes the ratio between the patch area and the smallest circumscribing circle of the patch and characterises the compactness of the patch. CIRCLE_CV describes the differences among patches of the same class i in the landscape. Because it is scaled to the mean, it is easily comparable.

Because the metric is based on distances or areas please make sure your data is valid using check_landscape.

Units

None

Range

CIRCLE_CV >= 0

Behaviour

Equals CIRCLE_CV if the related circumscribing circle is identical for all patches. Increases, without limit, as the variation of related circumscribing circles increases.

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).

See also

lsm_p_circle, mean,
lsm_c_circle_mn, lsm_c_circle_sd,
lsm_l_circle_mn, lsm_l_circle_sd, lsm_l_circle_cv

Examples

landscape <- terra::rast(landscapemetrics::landscape)
lsm_c_circle_cv(landscape)
#> # A tibble: 3 × 6
#>   layer level class    id metric    value
#>   <int> <chr> <int> <int> <chr>     <dbl>
#> 1     1 class     1    NA circle_cv  25.3
#> 2     1 class     2    NA circle_cv  23.7
#> 3     1 class     3    NA circle_cv  16.5