Graph-Tool GraphView Object

Question

I have a filtered graph generated using graph-tool's GraphView().

g = gt.GraphView(g, vfilt= label_largest_component(g, directed=False))

The original graph g has 10,069 vertices while the resulting graph has 9,197. However, using the new (filtered) graph, when I list the in-degrees using indeg = g.degree_property_map("in"), the total number of elements in list(indeg.a) is still 10,069. This becomes problematic when plotting the new filtered graph with 9,197 nodes where the vertex sizes are set as a function of indeg, essentially because of the mismatched number of elements.

The code snippet looks like this

g = load_graph("ppnet.xml")
g = GraphView(g, vfilt=label_largest_component(g, directed=False))
indeg = g.degree_property_map("in")
indeg.a = np.sqrt(indeg.a) + 2
graph_draw(g, vertex_size = indeg, vertex_fill_color=indeg, pos = sfdp_layout(g),
    vcmap=plt.cm.gist_heat, output_size=(400, 400), output="gc.png")

which when run, gives the following ValueError

ValueError: operands could not be broadcast together with shapes (10069,) (9197,) 

What is the proper way to add the intended style for GraphView objects?

Answer 1

Found a solution. I first created a copy of the GraphView object and then purged the vertices of this copy. Note that instead of retaining the variable name g, I introduced a new variable gc for clarity.

g = load_graph("ppnet.xml")
gc = GraphView(g, vfilt=label_largest_component(g, directed=False)).copy()
gc.purge_vertices()
indeg = gc.degree_property_map("in")
indeg.a = np.sqrt(indeg.a)+2
graph_draw(gc, vertex_size = indeg, vertex_fill_color=indeg, pos = sfdp_layout(gc),
    vcmap=plt.cm.gist_heat, output_size=(400, 400), output="gc.png")