Matplotlib savefig .ps


I have a problem with the function matplotlib.pyplot.savefig. I would
like to create a png and a ps image from a plot.
I try to save 2 specgrams on a page, with 2 000 000 points each.
I have no problem with the .png file which is 361 kB, but with the .ps
file, the size is huge : 450 MB!
The size is huge, and the running time is very long too.

So what can I do to reduce the file size and the running time?
I tried every options of the function savefig, but it didn't went better...

Thanks for your help,




Alexandre CANDELON
Ing?nieur d?veloppement TARANIS

3A Avenue de la Recherche Scientifique
45071 ORLEANS Cedex 2