How to save a figure remotely with pylab?

By default, matplotlib will use something like the TkAgg backend. This requires an X-server to be running.

While you can just use X-forwarding, there will be a noticeable lag as matplotlib tries to connect with the remote X-server. If you don't need to interact with the plot, it's often nicer to speed things up by avoiding an X-connection entirely.

If you want to make a plot without needing an X-server at all, use the Agg backend instead.

E.g. do something like this:

import matplotlib
matplotlib.use('Agg') # Must be before importing matplotlib.pyplot or pylab!
import matplotlib.pyplot as plt

fig = plt.figure()
plt.plot(range(10))
fig.savefig('temp.png')

If you want this to be the default behavior, you can modify your matplotlibrc file to use the Agg backend by default.

See this article for more information.

Try setting the DISPLAY variable to the appropriate value.

Graphics over the network using X11 work by the client (remote) computer having a DISPLAY environment variable that says where to draw the graphics. Typically it would be something like mydesktop.example.com:0.0 - then when an X11 program tries to draw something, it gets whizzed over the network to mydesktop.example.com, which is the machine you are sitting in front of (the X server) and up it pops.

Now, if the machine in front of you is Windows, then you'll need to get an X server from somewhere - cygwin/X11 or commercial eXceed will do nicely.

You also need to make sure security is handled - you cant just have anyone writing to your screen over the network.

How are you connecting to the remote machine? Because if you are going from a Linux box to another Linux box with ssh then the simple solution is probably 'Use ssh -X foo.example.com' to connect - this pipes the X11 connection over a local socket.

So, if ssh -X isnt the answer, can we have some more info on the operating systems involved please?