The DrL graph layout generator

DrL is a force-directed graph layout toolbox focused on real-world large-scale graphs, developed by Shawn Martin and colleagues at Sandia National Laboratories.

Usage

layout_with_drl(
  graph,
  use.seed = FALSE,
  seed = matrix(runif(vcount(graph) * 2), ncol = 2),
  options = drl_defaults$default,
  weights = NULL,
  dim = 2
)

with_drl(...)

Arguments

graph: The input graph, in can be directed or undirected.
use.seed: Logical scalar, whether to use the coordinates given in the seed argument as a starting point.
seed: A matrix with two columns, the starting coordinates for the vertices is use.seed is TRUE. It is ignored otherwise.
options: Options for the layout generator, a named list. See details below.
weights: The weights of the edges. It must be a positive numeric vector, NULL or NA. If it is NULL and the input graph has a ‘weight’ edge attribute, then that attribute will be used. If NULL and no such attribute is present, then the edges will have equal weights. Set this to NA if the graph was a ‘weight’ edge attribute, but you don't want to use it for the layout. Larger edge weights correspond to stronger connections.
dim: Either ‘2’ or ‘3’, it specifies whether we want a two dimensional or a three dimensional layout. Note that because of the nature of the DrL algorithm, the three dimensional layout takes significantly longer to compute.
...: Passed to layout_with_drl().

Value

A numeric matrix with two columns.

Details

This function implements the force-directed DrL layout generator.

The generator has the following parameters:

edge.cut: Edge cutting is done in the late stages of the algorithm in order to achieve less dense layouts. Edges are cut if there is a lot of stress on them (a large value in the objective function sum). The edge cutting parameter is a value between 0 and 1 with 0 representing no edge cutting and 1 representing maximal edge cutting.
init.iterations: Number of iterations in the first phase.
init.temperature: Start temperature, first phase.
init.attraction: Attraction, first phase.
init.damping.mult: Damping, first phase.
liquid.iterations: Number of iterations, liquid phase.
liquid.temperature: Start temperature, liquid phase.
liquid.attraction: Attraction, liquid phase.
liquid.damping.mult: Damping, liquid phase.
expansion.iterations: Number of iterations, expansion phase.
expansion.temperature: Start temperature, expansion phase.
expansion.attraction: Attraction, expansion phase.
expansion.damping.mult: Damping, expansion phase.
cooldown.iterations: Number of iterations, cooldown phase.
cooldown.temperature: Start temperature, cooldown phase.
cooldown.attraction: Attraction, cooldown phase.
cooldown.damping.mult: Damping, cooldown phase.
crunch.iterations: Number of iterations, crunch phase.
crunch.temperature: Start temperature, crunch phase.
crunch.attraction: Attraction, crunch phase.
crunch.damping.mult: Damping, crunch phase.
simmer.iterations: Number of iterations, simmer phase.
simmer.temperature: Start temperature, simmer phase.
simmer.attraction: Attraction, simmer phase.
simmer.damping.mult: Damping, simmer phase.

References

See the following technical report: Martin, S., Brown, W.M., Klavans, R., Boyack, K.W., DrL: Distributed Recursive (Graph) Layout. SAND Reports, 2008. 2936: p. 1-10.

Author

Shawn Martin (http://www.cs.otago.ac.nz/homepages/smartin/) and Gabor Csardi csardi.gabor@gmail.com for the R/igraph interface and the three dimensional version.

Examples


g <- as_undirected(sample_pa(100, m = 1))
l <- layout_with_drl(g, options = list(simmer.attraction = 0))
plot(g, layout = l, vertex.size = 3, vertex.label = NA)