patchcollection wihtout edgecolor and gradient filled patches

   p = PatchCollection(patches, alpha = 1.0,cmap = mpl.cm.Blues,
       linewidth="0.0",edgecolor="black",linewidth="0.0")

The documentation at http://matplotlib.sourceforge.net
/api/collections_api.html#matplotlib.collections.PatchCollection

has _plurals_ on the kwards (linewidths rather than linewidth) and
as such it works for me:

coll=matplotlib.collections.PatchCollection(
  patches,alpha=.5,linewidths=0.)

using matplotlib 0.99.0.

HTH, Vaclav