match_pts_to_graph: match_pts_to_graph

Description Usage Arguments Value Examples

Description

Match spatial points to a spatial graph which contains vertex coordindates

Usage

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match_pts_to_graph(verts, xy, connected = FALSE)

Arguments

verts

A data.frame of vertices obtained from dodgr_vertices(graph).

xy

coordinates of points to be matched to the vertices, either as matrix or sf-formatted data.frame.

connected

Should points be matched to the same (largest) connected component of graph? If FALSE and these points are to be used for a dodgr routing routine (dodgr_dists, dodgr_paths, or dodgr_flows_aggregate), then results may not be returned if points are not part of the same connected component. On the other hand, forcing them to be part of the same connected component may decrease the spatial accuracy of matching.

Value

A vector index into verts

Examples

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net <- weight_streetnet (hampi, wt_profile = "foot")
verts <- dodgr_vertices (net)
# Then generate some random points to match to graph
npts <- 10
xy <- data.frame (
                  x = min (verts$x) + runif (npts) * diff (range (verts$x)),
                  y = min (verts$y) + runif (npts) * diff (range (verts$y))
                  )
pts <- match_pts_to_graph (verts, xy)
pts # an index into verts
pts <- verts$id [pts]
pts # names of those vertices

dodgr documentation built on Jan. 31, 2021, 1:06 a.m.