spNetwork (version 0.2.1)

graph_checking: Topological error

Description

A utility function to find topological errors in a network.

Usage

graph_checking(lines, digits, max_search = 5, tol = 0.1)

Arguments

lines

A SpatialLinesDataFrame representing the network

digits

An integer indicating the number of digits to retain for coordinates

max_search

The maximum number of nearest neighbour to search to find close_nodes

tol

The minimum distance expected between two nodes. Under that values nodes are considered as too close and are returned in the results.

Value

A list with three elements. The first is a SpatialPointsDataFrame indicating for each node of the network to which component it belongs. The second is a SpatialPointsDataFrame with nodes that are too close one of each other. The second is a SpatialPointsDataFrame with the dangle nodes of the network.

Details

This function can be used to check for three common problems in networks: disconnected components, dangle nodes and close nodes. When a network has disconnected components, this means that several unconnected graphs are composing the overall network. This can be caused by topological errors in the dataset. Dangle nodes are nodes connected to only one other node. This type of node can be normal at the border of a network, but can also be caused by topological errors. Close nodes are nodes that are not coincident, but so close that they probably should be coincident.

Examples

# NOT RUN {
networkgpkg <- system.file("extdata", "networks.gpkg", package = "spNetwork", mustWork = TRUE)
mtl_network <- rgdal::readOGR(networkgpkg,layer="mtl_network", verbose=FALSE)
topo_errors <- graph_checking(mtl_network, 2)
# }