Jeff: Thanks very much for finding and fixing the bug! Plotting loops works fine for me now. Tiago: I can understand very well that it is a lot of work to maintain the two similar functions graphviz_draw() and graph_draw() at the same time. Still, it would be a pity if graphviz_draw() disappears completely in future versions of graph-tool. I'm using graphviz_draw() a lot because it has some features that graph_draw() doesn't have. In particular, graphviz can put text nicely into oval-shaped vertices. Cairo, however, produces large circles that hide much of the graph. Using the vertex property "aspect" is very slow and does not improve the plots much. Examples are available here: http://www.rolf-sander.net/tmp/graphviz.pdf http://www.rolf-sander.net/tmp/cairo.pdf Best regards Rolf -- Sent from: https://nabble.skewed.de/