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Connected components of metric graph

Source: R/metric_graph.R
graph_components.Rd

Class representing connected components of a metric graph.

Value

Object of R6Class for creating metric graph components.

Details

A list of metric_graph objects (representing the different connected components in the full graph) created from vertex and edge matrices, or from an sp::SpatialLines object where each line is representing and edge. For more details, see the vignette: vignette("metric_graph", package = "MetricGraph")

Public fields

graphs

List of the graphs representing the connected components.

n

The number of graphs.

sizes

Number of vertices for each of the graphs.

lengths

Total edge lengths for each of the graphs. Create metric graphs for connected components

Methods

Public methods

Method new()

Usage

graph_components$new(
  edges = NULL,
  V = NULL,
  E = NULL,
  by_length = TRUE,
  edge_weights = NULL,
  ...,
  lines = deprecated()
)

Arguments

edges

A list containing coordinates as m x 2 matrices (that is, of matrix type) or m x 2 data frames (data.frame type) of sequence of points connected by straightlines. Alternatively, you can also prove an object of type SpatialLinesDataFrame or SpatialLines (from sp package) or MULTILINESTRING (from sf package).

V

n x 2 matrix with Euclidean coordinates of the n vertices.

E

m x 2 matrix where each row represents an edge.

by_length

Sort the components by total edge length? If FALSE, the components are sorted by the number of vertices.

edge_weights

Either a number, a numerical vector with length given by the number of edges, providing the edge weights, or a data.frame with the number of rows being equal to the number of edges, where

...

Additional arguments used when specifying the graphs

lines

[Deprecated] Use edges instead.

vertex_unit

The unit in which the vertices are specified. The options are 'degree' (the great circle distance in km), 'km', 'm' and 'miles'. The default is NULL, which means no unit. However, if you set length_unit, you need to set vertex_unit.

length_unit

The unit in which the lengths will be computed. The options are 'km', 'm' and 'miles'. The default is vertex_unit. Observe that if vertex_unit is NULL, length_unit can only be NULL. If vertex_unit is 'degree', then the default value for length_unit is 'km'.

longlat

If TRUE, then it is assumed that the coordinates are given. in Longitude/Latitude and that distances should be computed in meters. It takes precedence over vertex_unit and length_unit, and is equivalent to vertex_unit = 'degree' and length_unit = 'm'.

tolerance

Vertices that are closer than this number are merged when constructing the graph (default = 1e-10). If longlat = TRUE, the tolerance is given in km.

Returns

A graph_components object.

Method get_largest()

Returns the largest component in the graph.

Usage

graph_components$get_largest()

Returns

A metric_graph object.

Method plot()

Plots all components.

Usage

graph_components$plot(edge_colors = NULL, vertex_colors = NULL, ...)

Arguments

edge_colors

A 3 x nc matrix with RGB values for the edge colors to be used when plotting each graph.

vertex_colors

A 3 x nc matrix with RGB values for the edge colors to be used when plotting each graph.

...

Additional arguments for plotting the individual graphs.

Returns

A ggplot object.

Method clone()

The objects of this class are cloneable with this method.

Usage

graph_components$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Examples

library(sp)
edge1 <- rbind(c(0, 0), c(1, 0))
edge2 <- rbind(c(1, 0), c(2, 0))
edge3 <- rbind(c(1, 1), c(2, 1))
edges <- list(edge1, edge2, edge3)

graphs <- graph_components$new(edges)
#> Starting graph creation...
#> LongLat is set to FALSE
#> Creating edges...
#> Setting edge weights...
#> Computing bounding box...
#> Setting up edges
#> Merging close vertices
#> Total construction time: 0.08 secs
#> Creating and updating vertices...
#> Storing the initial graph...
#> Computing the relative positions of the edges...
#> Extracting components...
#> Number of components: 2
#> Constructing graphs...
#> Processing component 1
#> Starting graph construction...
#> Starting graph creation...
#> LongLat is set to FALSE
#> Creating edges...
#> Setting edge weights...
#> Computing bounding box...
#> Setting up edges
#> Merging close vertices
#> Total construction time: 0.08 secs
#> Creating and updating vertices...
#> Storing the initial graph...
#> Computing the relative positions of the edges...
#> Processing component 2
#> Starting graph construction...
#> Starting graph creation...
#> LongLat is set to FALSE
#> Creating edges...
#> Setting edge weights...
#> Computing bounding box...
#> Setting up edges
#> Merging close vertices
#> Total construction time: 0.07 secs
#> Creating and updating vertices...
#> Storing the initial graph...
#> Computing the relative positions of the edges...
graphs$plot()