define_boundary {BoundaryStats}

Define the boundary elements of a SpatRaster with numeric data or boundary intensities

Description

Defines boundaries in a SpatRaster object by keeping a proportion of the cells with the highest boundary intensity values. If the SpatRaster contains trait values, the values can be converted to boundary/edge values (convert = T) using a Sobel-Feldman operator.

Usage

define_boundary(x, threshold = 0.2, convert = FALSE)

Arguments

x

A SpatRaster object.

threshold

A value between 0 and 1. The proportion of cells to keep as boundary elements. default = 0.2.

convert

logical. If TRUE, convert values of each cell from trait values to boundary intensities. default = FALSE.

Value

A SpatRaster object with cell values 1 for boundary elements and 0 for other cells

Author(s)

Amy Luo

References

Fortin, M.J. et al. (2000) Issues related to the detection of boundaries. Landscape Ecology, 15, 453-466. 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.

Examples

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

grassland_boundaries <- define_boundary(grassland, 0.1)