matplotlib-users Mailing List for matplotlib

On Sat, Jan 8, 2011 at 4:07 PM, Daniel Mader <
dan...@go...> wrote:
> Hello,
>
> I have a problem with the 3D plotting of PolyCollections with
> python-matplotlib-1.0.0 (on openSUSE 11.3 x86_64):
>
> instead of being correctly stacked as in the example
> http://matplotlib.sourceforge.net/examples/mplot3d/polys3d_demo.html,
> the plots are weirdly overlapping. The example works OK for me but I
> need a PolyCollection in order to plot the results of a couple of FEM
> simulations...
>
> Code is attached which demonstrates the problem. Any help is deeply
> appreciated!
>
> Thanks a million times in advance,
> best regards from Salzburg, Austria,
>
> Daniel
>
>
Daniel,
The stacking problem is fairly well known (although not very well
documented). However, this is not your bug.
I haven't exactly figure out what is wrong, but it appears that a fifth
polygon is being drawn or something that is connecting back to the (0, 0)
point. If you redefine your polygons a bit, you will see what I mean:
vertsQuad = [ [ (0,0), (0,1), (1,1), (1,0) ],
 [ (4,1), (2,3), (2,2), (3,1)],
 [ (0,1), (2,3), (2,2), (1,1)],
 [ (3,0), (3,1), (4,1), (4,0)]]
As an additional note, your for-loop later in the code is a bit wrong:
zpos = [0, 1, 2, 3, 4]
for i in zpos :
 ...
 zs = [zpos[i]]*len(vertsQuad)
In this case, you are using the values of zpos as both the z-location values
*and* as an index back to itself. Try something like this:
zpos = [0, 1, 2, 3, 4]
for zval in zpos :
 ...
 zs = [zval]*len(vertsQuad)
That way, the values in zpos can be any numerical value, in any order, and
it makes for easier reading.
I will look a little bit further for the cause of your problem, but you can
at least partly mitigate it by closing your polygon paths (this shouldn't be
necessary, but go figure...):
vertsQuad = [ [ (0,0), (0,1), (1,1), (1,0), (0,0) ],
 [ (4,1), (2,3), (2,2), (3,1), (4,1)],
 [ (0,1), (2,3), (2,2), (1,1), (0,1)],
 [ (3,0), (3,1), (4,1), (4,0), (3,0)]]
I hope this helps!
Ben Root

Hello,
I have a problem with the 3D plotting of PolyCollections with
python-matplotlib-1.0.0 (on openSUSE 11.3 x86_64):
instead of being correctly stacked as in the example
http://matplotlib.sourceforge.net/examples/mplot3d/polys3d_demo.html,
the plots are weirdly overlapping. The example works OK for me but I
need a PolyCollection in order to plot the results of a couple of FEM
simulations...
Code is attached which demonstrates the problem. Any help is deeply appreciated!
Thanks a million times in advance,
best regards from Salzburg, Austria,
Daniel

Hi,
On 8 January 2011 18:57, OKB (not okblacke) <bre...@br...> wrote:
> Is there a simple way to get a
> histogram that does not bin any values together at all, but simply
> creates one bar for each distinct value in the dataset?
You can just use the bins keyword to plt.hist (or np.hist):
plt.hist ( x, bins=np.unique ( x ) )
Jose

 	A straightforward question: Is there a simple way to get a 
histogram that does not bin any values together at all, but simply 
creates one bar for each distinct value in the dataset?
-- 
--OKB (not okblacke)
Brendan Barnwell
"Do not follow where the path may lead. Go, instead, where there is
no path, and leave a trail."
	--author unknown