Alias for dodgr_dists

dodgr_distances(graph, from = NULL, to = NULL, shortest = TRUE,
heap = "BHeap", parallel = TRUE, quiet = TRUE)

Arguments

graph data.frame or equivalent object representing the network graph (see Notes) Vector or matrix of points from which route distances are to be calculated (see Notes) Vector or matrix of points to which route distances are to be calculated (see Notes) If FALSE, calculate distances along the fastest rather than shortest routes (see Notes). Type of heap to use in priority queue. Options include Fibonacci Heap (default; FHeap), Binary Heap (BHeap), Radix, Trinomial Heap (TriHeap), Extended Trinomial Heap (TriHeapExt, and 2-3 Heap (Heap23). If TRUE, perform routing calculation in parallel (see details) If FALSE, display progress messages on screen.

Value

square matrix of distances between nodes

Examples

# A simple graph
graph <- data.frame (from = c ("A", "B", "B", "B", "C", "C", "D", "D"),
to = c ("B", "A", "C", "D", "B", "D", "C", "A"),
d = c (1, 2, 1, 3, 2, 1, 2, 1))
dodgr_dists (graph)#>   A B C D
#> A 0 1 2 3
#> B 2 0 1 2
#> C 2 2 0 1
#> D 1 2 2 0
# A larger example from the included [hampi()] data.
graph <- weight_streetnet (hampi)
from <- sample (graph$from_id, size = 100) to <- sample (graph$to_id, size = 50)
d <- dodgr_dists (graph, from = from, to = to)
# d is a 100-by-50 matrix of distances between from and to# NOT RUN {
# a more complex street network example, thanks to @chrijo; see
# https://github.com/ATFutures/dodgr/issues/47

xy <- rbind (c (7.005994, 51.45774), # limbeckerplatz 1 essen germany
c (7.012874, 51.45041)) # hauptbahnhof essen germany
xy <- data.frame (lon = xy [, 1], lat = xy [, 2])
essen <- dodgr_streetnet (pts = xy, expand = 0.2, quiet = FALSE)
graph <- weight_streetnet (essen, wt_profile = "foot")
d <- dodgr_dists (graph, from = xy, to = xy)
# First reason why this does not work is because the graph has multiple,
# disconnected components.
table (graph$component) # reduce to largest connected component, which is always number 1 graph <- graph [which (graph$component == 1), ]
d <- dodgr_dists (graph, from = xy, to = xy)
# should work, but even then note that
table (essen$level) # There are parts of the network on different building levels (because of # shopping malls and the like). These may or may not be connected, so it may be # necessary to filter out particular levels index <- which (! (essen$level == "-1" | essen$level == "1")) # for example library (sf) # needed for following sub-select operation essen <- essen [index, ] graph <- weight_streetnet (essen, wt_profile = "foot") graph <- graph [which (graph$component == 1), ]
d <- dodgr_dists (graph, from = xy, to = xy)
# }