Standard deviation fractal dimension index (Shape metric)
lsm_l_frac_sd(landscape, directions = 8)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).
$$FRAC_{SD} = sd(FRAC[patch_{ij}])$$ where \(FRAC[patch_{ij}]\) equals the fractal dimension index of each patch.
FRAC_SD is a 'Shape metric'. The metric summarises the landscape as the standard deviation of the fractal dimension index of all patches in the landscape. The fractal dimension index is based on the patch perimeter and the patch area and describes the patch complexity.
None
FRAC_SD>= 0
Equals FRAC_SD = 0 if the fractal dimension index is identical for all patches. Increases, without limit, as the variation of the fractal dimension indices 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/
Mandelbrot, B. B. 1977. Fractals: Form, Chance, and Dimension. San Francisco. W. H. Freeman and Company.
lsm_p_frac,
sd,
lsm_c_frac_mn,
lsm_c_frac_sd,
lsm_c_frac_cv,
lsm_l_frac_mn,
lsm_l_frac_cv