dodgr_isoverts
Calculate isodistance or isochrone contours from specified points, and return
lists of all network vertices contained within the contours. Function is
fully vectorized to calculate accept vectors of central points and vectors
defining multiple isochrone thresholds. Provide one or more dlim values for
isodistances, or one or more tlim values for isochrones.
dodgr_isoverts(graph, from = NULL, dlim = NULL, tlim = NULL, heap = "BHeap")
graph |
|
from |
Vector or matrix of points from which isodistances or isochrones are to be calculated. |
dlim |
Vector of desired limits of isodistances in metres. |
tlim |
Vector of desired limits of isochrones in seconds |
heap |
Type of heap to use in priority queue. Options include
Fibonacci Heap (default; |
A single data.frame of vertex IDs, with columns denoting the from
points and tlim value(s). The isochrones are given as id values and
associated coordinates of the series of points from each from point at the
specified isochrone times.
Isoverts are calculated by default using parallel computation with the
maximal number of available cores or threads. This number can be reduced by
specifying a value via RcppParallel::setThreadOptions (numThreads = <desired_number>).
Other distances:
dodgr_distances(),
dodgr_dists_categorical(),
dodgr_dists(),
dodgr_flows_aggregate(),
dodgr_flows_disperse(),
dodgr_flows_si(),
dodgr_isochrones(),
dodgr_isodists(),
dodgr_paths(),
dodgr_times()
## Not run:
# Use osmdata package to extract 'SC'-format data:
library (osmdata)
dat <- opq ("hampi india") %>%
add_osm_feature (key = "highway") %>%
osmdata_sc ()
graph <- weight_streetnet (dat)
from <- sample (graph$.vx0, size = 100)
tlim <- c (5, 10, 20, 30, 60) * 60 # times in seconds
x <- dodgr_isoverts (graph, from = from, tlim)
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.