The function getColors returns the colors associated to the nodes of
a gGraph object, based on a specified node attribute.
Usage
getColors(x, ...)
# S4 method for gGraph
getColors(x, nodes = "all", attr.name, col.rules = NULL, ...)Arguments
- x
a valid gGraph.
- ...
other arguments passed to other methods.
- nodes
a vector of character strings or of integers identifying nodes by their name or their index. Can be "all", in which case all nodes are considered.
- attr.name
a character string indicating the name of node attribute to be used to define colors.
- col.rules
a matrix giving the rules for plotting attribute values with different colors. See details.
Details
Colors are based on a node attribute, that is, on a column of the
nodes.attr data.frame. This attribute should have a finite number of
values, and would most likely be a factor. Correspondence between values of
this variable and colors must be provided in the @meta\$color slot,
or as col.rules argument. Color rules mus be provided as a two-column
matrix; the first column contains values of a node attribute, and is named
after this attribute; the second must be named "color", and contain valid
colors.
See example section to know how this slot should be designed.
Examples
worldgraph.10k # there is a node attribute 'habitat'
#>
#> === gGraph object ===
#>
#> @coords: spatial coordinates of 10242 nodes
#> lon lat
#> 1 -180.0000 90.00000
#> 2 144.0000 -90.00000
#> 3 -33.7806 27.18924
#> ...
#>
#> @nodes.attr: 1 nodes attributes
#> habitat
#> 1 sea
#> 2 sea
#> 3 sea
#> ...
#>
#> @meta: list of meta information with 2 items
#> [1] "$colors" "$costs"
#>
#> @graph:
#> A graphNEL graph with undirected edges
#> Number of Nodes = 10242
#> Number of Edges = 6954
worldgraph.10k@meta$color
#> habitat color
#> 1 sea blue
#> 2 land green
#> 3 mountain brown
#> 4 landbridge light green
#> 5 oceanic crossing light blue
#> 6 deselected land lightgray
head(getNodes(worldgraph.10k))
#> [1] "1" "2" "3" "4" "5" "6"
head(getColors(worldgraph.10k, res.type = "vector", attr.name = "habitat"))
#> 1 2 3 4 5 6
#> "blue" "blue" "blue" "blue" "blue" "blue"