graph
objects.
"plot"(x, y, ..., name = "", subGList = list(), attrs = list(), nodeAttrs = list(), edgeAttrs = list(), recipEdges = c("combined", "distinct"))
"plot"(x, y, edgeAttrs = list(), ..., main = NULL, cex.main = NULL, col.main = "black", sub = NULL, cex.sub = NULL, col.sub = "black", drawNode = drawAgNode, xlab, ylab, mai)
graph
object to plotagopen
graph
object to be plotted. If provided, these subgraphs
will be clustered visually. If not provided, no clusters will be used.agopen
drawAgNode
usage
section corresponds to the
graph
class in the graph
package. It will convert the
graph
object into an object of class Ragraph
by using
Graphviz to perform the layout. Then it will call the plot method for
Ragraph
. The plot.graph
method is nothing more then a
wrapper that calls agopen
and plot.Ragraph
. The second plot method in the usage
section is for the
Ragraph
class, which describes a Graphviz structure of a
graph. This method will extract necessary information from the object
and use it to plot the graph. Users can specify arbitrary drawing functions for the nodes of the
Ragraph
with the drawNode
argument, although caution is
urged. The default drawing function for
all nodes is drawAgNode
, which will draw a basic circle,
ellipse or rectangle according to the layout specifications for each
node. If supplying a custom function, users are encouraged to look at
the code of this function for a more clear picture of the information
required to properly draw a node. Users can specify either one
custom function to be used for all nodes or a list (where length is
equal to the nubmer of nodes) of functions where the Nth element in
the list provides the drawing function for the Nth node, and every
function will take four parameters - the first is an object of class
AgNode
representing the node itself and the second is an object
of class xyPoint
representing the upper right corner of
the Graphviz plotting region (where the lower left is 0,0
).
The third parameter, attrs
is a node attribute list and
represents post-layout attribute changes where the user wants to
override values present in the layout. The last argument,
radConv
is a divisor to the radius and is used to convert from
Graphviz
units to R plotting units. Outside of the first
argument, the rest of these (particularly radConv
which
generally shouldn't be specifically set) do not need to be set by the
user, but any drawing function must have them as parameters. The attrs
list requires a particular format. It must be of
length 3 with names graph
, node
, and edge
. Each
of these elements themselves are lists - such that an element of
graph
corresponds to a graph element. A full listing of
attributes and their possible settings is available at
http://www.research.att.com/~erg/graphviz/info/attrs.html
. All
attribute values should be entered as character strings (even if the
requested value is to be otherwise). The nodeAttrs
list is used to specify attributes on a
particular node, instead of for all nodes. The format of this list is
such that the elements correspond to attributes (the name of the
element is used to note which attribute) and each element contains a
named vector. The names of the vector denote which nodes are having
this attribute set and the values in the vector specify the value. The edgeAttrs
list is identical in format to nodeAttrs
.
However, the name of the edges is in a particular format where an edge
between x and y is named x~y
. Note that even in an undirected
graph that x~y
is not the same as y~x
- the name must be
in the same order that the edge was defined as having.Ragraph
object used for plottinggraphNEL-class
, graph-class
# WHY DOES THIS NOT WORK IN CHECK?
# V <- letters[1:10]
# M <- 1:4
# g1 <- randomGraph(V, M, .2)
# plot(g1)
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