Re: [spyder] This call to matplotlib.use() has no effect

[David Verelst]

Hi, The Spyder consoles start already with Matplotlib (and pyplot), NumPy and SciPy imported. This means that you can't change the Matplotlib backend anymore since pyplot/pylab module is already imported when the console starts. Remember that you have to set the Matplotlib backend before importing pyplot. This also explains why in a stand alone python console, one not connected to spyder, does work as you expected: there's not a single external module imported upon startup. To change the Matplotlib backend Spyder uses: Preferences > Console > External modules > Matplotlib GUI backend To my understanding (note that I am not a developer), these imports are done in order to get some of Spyders other features to work (e.g. monitor). I assume that, theoretically, you could disable the Matplotlib/pyplot imports upon the startup of a console, but I am not sure where exactly this should be done in the code, and what other consequences this will have. Maybe a note on Matplotlib backends should be added to the documentation (for instance in the Console section)? I don't mind drafting a proposed change for this somewhere this week. Regards, David On 19/03/12 04:15, ben h wrote: I want to set the matplotlib backend from within my script. I can do this if I run my script from a shell/terminal, but from Spyder I get an error.  Here is the full error message: /usr/local/lib/python2.6/dist-packages/matplotlib-1.0.1-py2.6-linux-x86_64.egg/matplotlib/__init__.py:888: UserWarning: This call to matplotlib.use() has no effect because the the backend has already been chosen; matplotlib.use() must be called *before* pylab, matplotlib.pyplot, or matplotlib.backends is imported for the first time. if warn: warnings.warn(_use_error_msg) I searched this list and found this old message that seems related: https://groups.google.com/d/msg/spyderlib/rAWkNkGWpK0/1fII0P5leowJ Here is a snippet from my script: #!/usr/bin/env python """     Bore data plotting routine """ # if needed set the backend before importing pyplot: import matplotlib matplotlib.use("PS") import numpy as np import matplotlib.pyplot as plt from matplotlib import rc ... commands ... -- You received this message because you are subscribed to the Google Groups "spyder" group. To view this discussion on the web visit https://groups.google.com/d/msg/spyderlib/-/tH5mr59C11MJ. To post to this group, send email to spyderlib@googlegroups.com. To unsubscribe from this group, send email to spyderlib+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/spyderlib?hl=en. -- You received this message because you are subscribed to the Google Groups "spyder" group. To post to this group, send email to spyderlib@googlegroups.com. To unsubscribe from this group, send email to spyderlib+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/spyderlib?hl=en.