ipython --pylab on cygwin: TclError: no display name and no $DISPLAY environment variable
Type startxwin into the cygwin terminal ( you will need the X11 libraries available from the cygwin setup.exe ) You can then run ipython --pylab from the new terminal window and a command like plot(range(10)) which will open a new window but you will need to also call plt.draw() for the plot to appear unlike in native pylab, the control over windows for the plots in cygwin is also poor compared to native pylab.
I didn't need to edit any setup files in this process, you may need to 'pip uninstall matplotlib' and reinstall until you have the required libraries installed via the cygwin setup.exe ( tkinter and I believe X11-devel libraries are required ).
Get setuptools via ez_setup.py
wget http://peak.telecommunity.com/dist/ez_setup.pypython ez_setup.pyeasy_install pip pip install numpy pip install ipythonpip install matplotlib