If anyone still wants old MatPlotLib 1.0.0 for some reason :

1) download from my Harmattan repository :
python-matplotlib-data_1.0.0-1_all.deb
python-matplotlib_1.0.0-1_armel.deb

2) install dependencies, as root in Terminal :
# apt-get install python-central python-support python-numpy python-dateutil python-gobject python-cairo

3) install MatPlotLib 1.0.0, again as root in Terminal, in the same directory where the files where downloaded :
# dpkg -i python-matplotlib-data_1.0.0-1_all.deb
# dpkg -i python-matplotlib_1.0.0-1_armel.deb

4) configure MatPlotLib 1.0.0, in Terminal as root :
# mkdir /usr/lib/python2.6/dist-packages/matplotlib/mpl-data
As user :
$ cd ~
$ rm -rf .matplotlib
$ mkdir .matplotlib
$ echo 'datapath : /usr/share/matplotlib/mpl-data' > .matplotlib/matplotlibrc
MatPlotLib 1.0.0 has no interactive graphical backend, so "show()" doesn't work, instead use "savefig" command to save plots to files.

MatPlotLib 1.2.0 is a lot simpler to install (see 1st post) and has more features on MeeGo Harmattan. See the benchmark of MatPlotLib 1.0.0 x 1.2.0 in the previous post.