Calculate matrix of pair-wise travel times between points.

dodgr_times(graph, from = NULL, to = NULL, shortest = FALSE, heap = "BHeap")

graph | A |
---|---|

from | Vector or matrix of points |

to | Vector or matrix of points |

shortest | If |

heap | Type of heap to use in priority queue. Options include
Fibonacci Heap (default; |

square matrix of distances between nodes

# 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` if (FALSE) { # 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) }