The code below is a stripped down version of the way i am implementing a
clip operation, but it is slow and memory inefficient. Is there a way to
do this without looping or just faster, perhaps with a
PolygonCollection?
I have code that finds the perimeter path of a triangulation like this,
but it turns out that my topology is not well formed enough for it to
work. Is there a hidden matplotlib method to combine or dissolve
Polygons/Patches?
Thanks,
Alex

import matplotlib.tri as Tri
import matplotlib.patches as patches
tri = Tri.Triangulation(lonn,latn,triangles=nv)
for triangle in tri.triangles:
p = patches.Polygon(
numpy.vstack(
(lonn[triangle].T,latn[triangle].T,)
).T
)
m.imshow(zi, norm=CNorm, cmap=colormap, clip_path=p)
