#12798: list_plot3d plots extraneous points at z=0 and doesn't take color or
rgbcolor as keywords
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Reporter: ppurka | Owner:
jdemeyer
Type: defect | Status:
needs_work
Priority: major | Milestone:
sage-5.6
Component: graphics | Resolution:
Keywords: list_plot3d, sd40.5 | Work issues:
Report Upstream: N/A | Reviewers:
Karl-Dieter Crisman, Punarbasu Purkayastha, Jeroen Demeyer
Authors: Punarbasu Purkayastha, Karl-Dieter Crisman | Merged in:
Dependencies: | Stopgaps:
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Comment (by ppurka):
Replying to [comment:53 jdemeyer]:
> Replying to [comment:52 vbraun]:
> Seriously, you're arguing that rendering 3D figures with NaN coordinates
is a good thing? I find it hard to believe that rendering a figure with
2000 faces (half of which aren't drawn due to !NaNs) is faster than first
removing the offending faces and rendering a figure with 1000 faces.
I haven't looked at if it is Sage which is doing the rendering. But if
Sage is trying to actually ''plot/render'' the points - the nans are
specific 3D points `(x,y,nan)`, not entire faces - then it is doing
something very inefficient. What I would expect any reasonable plotting
routine to do is simply ignore all the points which are not finite real
numbers while rendering the plot. This is no different than the procedure
of looping through the points and discarding them before providing them to
the same plotting routine. Maybe you can have special algorithms for
quickly discarding "faces" or larger collections of adjacent points, while
generating a set of interpolated points. But this is useful if we control
all aspects of 3D plotting in Sage itself.
Note that we are ''not'' generating the grid - the grid is being provided
by mpl after interpolation. Anyway, the slowdown is architecture specific
(there's speedups on intel, as I mentioned before) and triggered only on
doctest mode; and if you would like it to stay that way then so be it.
Only reasonable way to fix `list_plot3d` if you don't want to allow nans
is to rewrite half of the 3D plotting methods (`ParametricSurface`), but I
don't have the time or inclination to do this now.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/12798#comment:55>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
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