dodgr_isochrones
Calculate isochrone contours from specified points. Function is fully vectorized to calculate accept vectors of central points and vectors defining multiple isochrone thresholds.
dodgr_isochrones(graph, from = NULL, tlim = NULL, heap = "BHeap")
graph |
|
from |
Vector or matrix of points from which isochrones are to be calculated. |
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 isochrones as points sorted anticlockwise
around each origin (from) point, 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.
Isochrones 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_isodists(),
dodgr_isoverts(),
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_isochrones (graph, from = from, tlim)
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.