Ox {BoundaryStats}

Average minimum distance from x boundary elements to nearest y boundary element.

Description

Statistical test for the average minimum distance between each boundary element in raster x and the nearest boundary element in raster y. Uses Euclidean distance. The boundaries of trait x depend on the boundaries of trait y.

Usage

Ox(x, y, null_distrib)

Arguments

x

A SpatRaster object with boundary elements.

y

A SpatRaster object with boundary elements.

null_distrib

A list of probability functions output from overlap_null_distrib().

Value

The average minimum distance and a p-value.

Author(s)

Amy Luo

References

Jacquez, G.M., Maruca,I S. & Fortin,M.-J. (2000) From fields to objects: A review of geographic boundary analysis. Journal of Geographical Systems, 3, 221, 241. Fortin, M.-J., Drapeau, P. & Jacquez, G.M. (1996) Quantification of the Spatial Co-Occurrences of Ecological Boundaries. Oikos, 77, 51-60.

Examples

data(T.cristatus)
T.cristatus <- terra::rast(T.cristatus_matrix, crs = T.cristatus_crs)
terra::ext(T.cristatus) <- T.cristatus_ext

data(grassland)
grassland <- terra::rast(grassland_matrix, crs = grassland_crs)
terra::ext(grassland) <- grassland_ext

Tcrist_ovlp_null <- overlap_null_distrib(T.cristatus, grassland, rand_both = FALSE,
  x_cat = TRUE, n_iterations = 100, x_model = 'random_cluster')
Tcrist_boundaries <- categorical_boundary(T.cristatus)
grassland_boundaries <- define_boundary(grassland, 0.1)

Ox(Tcrist_boundaries, grassland_boundaries, Tcrist_ovlp_null)