Matplotlib doesn't display graph in virtualenv

Question

I have pip installed matplotlib in my virtualenv and I am trying to plot a simple graph. I use Eclipse and PyDev. When I run the script from Eclipse it doesn\'t display any grap

Answer 1

First off, you might want to check out:

http://matplotlib.org/faq/installing_faq.html#matplotlib-compiled-fine-but-nothing-shows-up-when-i-use-it

To see what's going wrong, check out the matplotlib using git instead of either pip or easy_install. We're going to do a more manual install:

git clone git@github.com:matplotlib/matplotlib.git
cd matplotlib
python setup.py

This will print out the configuration of what pip or easy_install would have done. Look through the "OPTIONAL BACKEND DEPENDENCIES" and make sure that some of the ones that produce windows are enabled (Tkinter, Gtk+, Mac OS X native, Qt, Cairo, etc.). If you see that none of these are available, then you need to install some of these libraries for your operating system before you continue installing matplotlib.

After installing say, Tk (on ubuntu: sudo apt-get install tcl-dev tk-dev), then when you re-run

python setup.py

you will see that the Tk backend is enabled. Proceeding with

python setup.py build && python setup.py install

should get you up and running... but at that point you might even just delete the whole git clone directory and go back to installing with pip.

Answer 2

I had the same issue, and installing matplotlib using easy_install instead of pip did not solve it. In the end, I found out that the problem was simply that matplotlib could not find any backend for plotting.

I solved it by doing the following (I am using Debian wheezy):

pip uninstall matplotlib
sudo apt-get install tcl-dev tk-dev
pip install matplotlib

Answer 3

Your code works inside my virtualenv on OSX 10.7 with Python 2.7:

What version of Python are you using inside your virtualenv? My guess is that either you have not installed a matplotlib dependency or your installation of an installed dependency was not properly performed. On Python 2.7 here is what I did to install matplotlib. Can you try these steps in a new virtualenv and see if it works for you?

pip install numpy
pip install scipy
easy_install matplotlib

Answer 4

If you have a version of matplotlib installed on your system version of python, then you can link to the system version of matplotlib. On my machine I did the following:

cd $VIRTUAL_ENV/lib/python2.7/site-packages
ln -s /usr/lib/pymodules/python2.7/matplotlib .
ln -s /usr/lib/pymodules/python2.7/matplotlib-1.1.1rc .

This avoids many of the problems with getting matplotlib to work in the virtualenv but limits you to using the system version of matplotlib (which on this machine is not too bad).

This method also allows you to use the --no-site-packages, but still have matplotlib work for you.

Answer 5

I am using Ubuntu 12.04 and Python 2.7.3 on my computer and when I use the matplotlib 1.2.0 in my virtualenv, the show() did not work until I upgrade it to the 1.2.1... All the bugs I had previous went away...

By doing this you will install all the dependencies of the matplotlib:

sudo apt-get build-dep python-matplotlib

To get the latest version of the matplotlib you can use:

pip install matplotlib

or upgrade it:

pip install matplotlib --upgrade