matplotlib.pyplot documentation

[ast]

hello

I got this module documentation with help(matplotlib.pyplot)

for each function there is a demo file, for example:

    barbs(*args, **kw)
        Plot a 2-D field of barbs.
....
     **Example:**
        
     .. plot:: mpl_examples/pylab_examples/barb_demo.py

but I dont find the barb_demo.py on my computer, I made a 
full search on C:/Python34/ and it's failed

Do you know where these demo files are located ?
(windows vista, python 3.4)

thx