sfdp_layout#

graph_tool.draw.sfdp_layout(g, vweight=None, eweight=None, pin=None, C=0.2, K=None, p=2.0, theta=0.6, max_level=15, r=1.0, kc=10, groups=None, gamma=0.1, mu=2.0, kappa=1.0, rmap=None, R=1, init_step=None, cooling_step=0.95, adaptive_cooling=True, epsilon=0.01, max_iter=0, pos=None, multilevel=None, coarse_method='hybrid', mivs_thres=0.9, ec_thres=0.75, weighted_coarse=False, verbose=False)[source]#

Obtain the SFDP spring-block layout of the graph.

Parameters:

gGraph: Graph to be used.
vweightVertexPropertyMap (optional, default: None): A vertex property map with the respective weights.
eweightEdgePropertyMap (optional, default: None): An edge property map with the respective weights.
pinVertexPropertyMap (optional, default: None): A vertex property map with boolean values, which, if given, specify the vertices which will not have their positions modified.
Cfloat (optional, default: 0.2): Relative strength of repulsive forces.
Kfloat (optional, default: None): Optimal edge length. If not provided, it will be taken to be the average edge distance in the initial layout.
pfloat (optional, default: 2): Repulsive force exponent.
thetafloat (optional, default: 0.6): Quadtree opening parameter, a.k.a. Barnes-Hut opening criterion.
max_levelint (optional, default: 15): Maximum quadtree level.
rfloat (optional, default: 1.): Strength of attractive force between connected components.
kcint (optional, default: 10): Number of connected components to subsample.
groupsVertexPropertyMap or list of list of integers (optional, default: None): A vertex property map with group assignments. Vertices belonging to the same group will be put close together. Optionally, this can take an hierarchical partition, represented by a list of lists, where the list above correspond to the partition of the list below.
gammafloat or list of floats (optional, default: .1): Strength of the attractive force between nodes of the same group to their center of mass. In case of a hierarchical partition, this should correspond to a list of floats, containing the strenghts for each hierarchical level. This option has no effect if groups is None.
rmapVertexPropertyMap (optional, default: None): Vertex rank to be used around to order them preferentially in the \(y\) direction.
Rfloat (optional, default: 1.0): Strength of the rank ordering in the \(y\) direction.
init_stepfloat (optional, default: None): Initial update step. If not provided, it will be chosen automatically.
cooling_stepfloat (optional, default: 0.95): Cooling update step.
adaptive_coolingbool (optional, default: True): Use an adaptive cooling scheme.
epsilonfloat (optional, default: 0.01): Relative convergence criterion.
max_iterint (optional, default: 0): Maximum number of iterations. If this value is 0, it runs until convergence.
posVertexPropertyMap (optional, default: None): Initial vertex layout. If not provided, it will be randomly chosen.
multilevelbool (optional, default: None): Use a multilevel layout algorithm. If None is given, it will be activated based on the size of the graph.
coarse_methodstr (optional, default: "hybrid"): Coarsening method used if multilevel == True. Allowed methods are "hybrid", "mivs" and "ec".
mivs_thresfloat (optional, default: 0.9): If the relative size of the MIVS coarse graph is above this value, the coarsening stops.
ec_thresfloat (optional, default: 0.75): If the relative size of the EC coarse graph is above this value, the coarsening stops.
weighted_coarsebool (optional, default: False): Use weighted coarse graphs.
verbosebool (optional, default: False): Provide verbose information.

Returns:

posVertexPropertyMap: A vector-valued vertex property map with the coordinates of the vertices.

Notes

This algorithm is defined in [hu-multilevel-2005], and has complexity \(O(V\log V)\).

References

[hu-multilevel-2005]

Yifan Hu, “Efficient and High Quality Force-Directed Graph”, Mathematica Journal, vol. 10, Issue 1, pp. 37-71, (2005) http://www.mathematica-journal.com/issue/v10i1/graph_draw.html

Examples

>>> g = gt.price_network(3000)
>>> pos = gt.sfdp_layout(g)
>>> gt.graph_draw(g, pos=pos, output="graph-draw-sfdp.pdf")
<...>

../_images/graph-draw-sfdp.png — SFDP layout of a Price network.#

sfdp_layout

Contents

sfdp_layout#