Answer by fidbc for Hi all:Given a combinatorial graph (the nodes and edges type) $g$, what are the valid vertex_shape options for g.plot()? I can't find them in the Sage reference manual. I want to make square vertices.Thanks.

Hi, Sage uses matplotlib to plot graphs, and valid vertex shapes seem to be valid matplotlib markers, you chan check the matplotlib [documentation](http://x0.no/3pcb) for some other valid markers. If you want squares, then you can try, say sage: g=graphs.PetersenGraph();gp=g.graphplot() sage: gp.set_vertices(vertex_shape='s');gp.plot() Apparently changing vertex shapes is still not available for Multi-edged Digraphs though.