[vtkusers] VTK CVS + wxPython...

[Charl P. Botha]

Andrea Gavana wrote:
> Mhm... I thought to be immune from C/C++ things. I just switched from Matlab to
> Python because I was impressed by the Python capabilities (and also by the
> speed/easy of use of VTK, that is also fairly well linked with Python). The 
> graphic part of Matlab is far poorer than the VTK one (for my applications, at
> least), and with Python there are almost no limits on what you can implement.
> Moreover, the integration of wxWindows in Python was just a charme for me,
> because the last thing on which Matlab could be superior (the GUI building
> process), now is old story. I built some small GUI using Boa Constructor and
> wxPython and I was really satisfied.
> Now, going back from Matlab/Python to C/C++ seems to me like going from the
> Pentium IV (and above) Era to the ENIAC Era... but I can easily make mistakes,
> viewing my lack of experience in Python/C/C++ related things.

Think about this: there is really NO reason for VTK via Python to be 
significantly slower than VTK via C++.  When I do for instance:

filterA.SetInput(filterA.GetOutput())
filterA.Update()

What do you think happens?  That's right, compiled C++ code executes.

When I add actors to a renderer and interact with that renderer, what do 
you think happens?  That's right, compiled C++ code executes.

The only difference is that I benefit from the extremely dynamic nature 
of Python and I can do things at runtime which many C++ programmers have 
  not yet been able to imagine.

In short: There is little reason for a *well-written* VTK-Python 
application to be slower than a VTK-C++ application.  Simply keep in 
mind that Python is for gluing and C++ is for processing.  Also, don't 
forget the well-known rule that 20% of your code is responsible for 80% 
of your execution time[1], and that is a conservative estimate.

Thanks,
Charl

[1] "Improving software productivity", Barry W. Boehm, "Computer", vol. 
20 no. 9, 1987

-- 
charl p. botha http://cpbotha.net/ http://visualisation.tudelft.nl/