Re: [Visualpython-users] speed

[Guy K. K. <g....@ma...>]

The weekend before last I gave a presentation at (the first) Kiwi PyCon on 
live data plotting and visualisation. I have mainly focused on (2D and 3D) 
plotting tools, but due to its unique features also included Visual Python 
into the mix.

One of these unique features was speed. When it comes to the rendering of 
individual, unrelated objects, I have not seen anything faster than Visual. 
Some tools (maybe Mayavi) may be faster (or as fast) on structured data (that 
is e. g. vector fields in a cartesian array), but whenever I had to 
individually create and manage many data points, Visual was just the best in 
speed as compared with the other tools I'm familiar with.

Having said that, Mayavi also provides an API that tries to be (somewhat) 
compatible to Visual (I think to Visual 3.x). But it wasn't nearly as fast as 
Visual. If you for example run the doublependulum.py example from both, you'll 
be amazed how speedy the pendulum swings by, and that's just with less than 10 
rendered objects. But there also performance can be increased by setting the 
environment variable ETS_TOOLKIT=qt4 (to use the Qt4 backend, it's using "wx" 
by default). Still, speed is not nearly as fast, due to the fact that Mayavi 
goes through these abstraction layers:

	Python -> Traits -> VTKPython -> VTK -> OpenGL

And Visual goes

	Python -> C++ -> OpenGL

Of course, Mayavi has got grand additional nifty features due to that, but 
they do hinder execution speed quite significantly.

My slides of the talk are here:

http://www.slideshare.net/XEmacs/python-data-plotting-and-visualisation-
extravaganza

And a paper is soon to be available in The Python Paper Monograph Series issue 
for the Kiwi PyCon proceedings (see http://pythonpapers.org)

Guy

-- 
Guy K. Kloss
Institute of Information and Mathematical Sciences
Te Kura Pūtaiao o Mōhiohio me Pāngarau
Massey University, Albany (North Shore City, Auckland)
473 State Highway 17, Gate 1, Mailroom, Quad B Building
voice: +64 9 414-0800 ext. 9585   fax: +64 9 441-8181
G....@ma... http://www.massey.ac.nz/~gkloss