Hi, I am trying to generate plots for communities detected by another
algorithm (outside graph-tool). The communities are overlapping and I wanted
to display something like nodes with multiple colors (like we have for
SBMs). For this I set a new vertex property and assign nodal memberships to
it. I assign a matrix which contains one hot vectors for each node's
community membership. So the matrix has shape n x g where n is the number of
nodes and g is the number of communities. When I use graph_draw like:

You're probably just passing the wrong type to vertex_pie_fractions, but we
have no way to know that as we're missing the minimal self-contained
example.

Thanks, Tiago. The issue was the fact that when you added vertices which
did not have any clusters associated with them (isolated nodes), there was
an error. This behavior should be fixed, if possible.