leastcostpath (version 1.8.7)

force_isotropy: Convert anisotropic cost surfaces to isotropic

Description

Averages transition values from-to adjacent cells

Usage

force_isotropy(cost_surface)

Value

TransitionLayer (gdistance package) Conductance surface where transition values from-to adjacent cells have been averaged

Arguments

cost_surface

TransitionLayer (gdistance package). Conductance surface

Author

Joseph Lewis

Details

force_isotropy averages (mean) the transition values from-to adjacent cells in a cost_surface. Through this, anisotropic cost functions (i.e. where movement down-slope is easier than movement up-slope) are converted to an isotropic cost function. When calculating an least cost path using the resultant surface, the least cost path from A-B and B-A will be the same. This is in contrast to anisotropic cost surfaces where the least cost path from A-B and B-A can differ.

References

Herzog, I (2020). Spatial Analysis Based On Cost Functions, in Gillings, M., Hacıgüzeller, P., Lock, G. Archaeological Spatial Analysis. Routledge. pp. 333-358. tools:::Rd_expr_doi("10.4324/9781351243858-18")

Examples

r <- raster::raster(system.file('external/maungawhau.grd', package = 'gdistance'))

slope_cs <- create_slope_cs(r, cost_function = 'tobler', neighbours = 16, max_slope = NULL)

slope_cs_iso <- force_isotropy(slope_cs)