Calculate the shortest paths between points on a raster

Calculate the shortest paths between points on a raster

tc_shortest_paths(x, from, to, direction = "out")

Arguments

x	tc_graph: an object of class tc_graph, as returned by tc_build_graph()
from	numeric or matrix: the points to calculate travel costs from. A two-element numeric vector or a 2-column matrix, or anything else accepted by raster::cellFromXY()
to	numeric or matrix: the points to calculate travel costs to. If missing, paths to all points in the raster will be returned
direction	string: "out" - calculate travel cost outwards from the 'from' points to the 'to' points "in" - calculate travel cost from the 'to' points to the 'from' points

Value

A list of paths (two-column matrices giving x and y points)

See also

tc_build_graph()

Examples

my_raster <- raster::raster(ext = raster::extent(c(153, 155, -56, -54)), res = c(0.5, 0.5),
                            crs = "+proj=longlat")
g <- tc_build_graph(my_raster)

## set random edge weights
g <- tc_set_edge_weights(g, values = runif(sum(tc_adj_matrix(g) > 0)))

## calculate shortest path
p <- tc_shortest_paths(g, from = c(153, -54), to = c(155, -56))
plot(p[[1]][, 1], p[[1]][, 2], type = "l", xlab = "", ylab = "")