Hello, It seems that maplotlib and graph_tool can't live in the same python file. When the following code is run from an ide (spyder or ninja) an error is produced: import matplotlib.pyplot as plt import graph_tool.all as gt import numpy as np x = np.arange(0,7,0.1) y =np.sin(x) plt.plot(x,y) yield the error: (test-graphtool-matplotlib.py:5555): Gtk-ERROR **: GTK+ 2.x symbols detected. Using GTK+ 2.x and GTK+ 3 in the same process is not supported Matplotlib was build with ubuntu 14.04: >>> print matplotlib.__version__ 1.3.1 and graph_tool was installed from a deb. When a similar code is run from an ipython notebook, there's no error! test-matplotlib-graph_tool.ipynb <http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com/file/n4025617/test-matplotlib-graph_tool.ipynb> jean-patrick -- View this message in context: http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com/... Sent from the Main discussion list for the graph-tool project mailing list archive at Nabble.com.