costDist: Cost-distance

In terra: Spatial Data Analysis

Cost-distance

Description

Use a friction (cost) surface to compute the cost-distance from any cell to the border of one or more target cells.

Distances are computed by summing local distances between cells, which are connected with their neighbors in 8 directions, and assuming that the path has to go through the centers of one of the neighboring raster cells.

Distances are multiplied with the friction, thus to get the cost-distance, the friction surface must express the cost per unit distance (speed) of travel.

Usage

## S4 method for signature 'SpatRaster'
costDist(x, target=0, scale=1, maxiter=50, filename="", ...) 

Arguments

x	SpatRaster
target	numeric. value of the target cells (where to compute cost-distance to)
scale	numeric. Scale factor. The cost distance is divided by this number
maxiter	numeric. The maximum number of iterations. Increase this number if you get the warning that costDistance did not converge
filename	character. output filename (optional)
...	additional arguments as for writeRaster

Value

SpatRaster

See Also

gridDist, distance

Examples

r <- rast(ncols=5, nrows=5, crs="+proj=utm +zone=1 +datum=WGS84", 
		xmin=0, xmax=5, ymin=0, ymax=5, vals=1)
r[13] <- 0
d <- costDist(r)
plot(d)
text(d, digits=1)

r <- rast(ncols=10, nrows=10,  xmin=0, xmax=10, ymin=0, ymax=10, 
		   vals=10, crs="+proj=utm +zone=1 +datum=WGS84")
r[5, 1] <- -10
r[2:3, 1] <- r[1, 2:4] <- r[2, 5] <- 0
r[3, 6] <- r[2, 7] <- r[1, 8:9] <- 0
r[6, 6:10] <- NA
r[6:9, 6] <- NA

d <- costDist(r, -10)
plot(d)
text(d, digits=1, cex=.8)

terra documentation built on Oct. 14, 2024, 5:07 p.m.