[Numpy-discussion] "moving window" in numpy

Bradford Cross bradford.n.cross@gmail....
Sun Nov 25 19:14:25 CST 2007


Hi Matthew,

I've been working on "rolling/windowed" libraries for quite a while.

I'm currently working on implementations for basic moment and rank
statistics - they are pretty much done and I am trying to maneuver them
into  apache commons math for java.

I am also interested in implementing these statistics for python/numpy and
R.  I have seen a little bit for R, but nothing yet for numpy.

/brad

On Nov 25, 2007 5:00 PM, Matthew Perry <perrygeo@gmail.com> wrote:

> Hi all,
>
>  I'm not sure if my terminology is familiar but I'm trying to do a
> "moving window" analysis (ie a spatial filter or kernel) on a 2-D
> array representing elevation. For example, a 3x3 window centered on
> each cell is used to calculate the derivate slope of that cell.
>
>  Can this easily be implemented using numpy?
>
>  Currently I have tried implementing in pure python loops (too slow)
> and c++ (fast but more difficult to compile, distribute, wrap in
> python calls, etc). I think a good solution would be to leverage numpy
> which is both fast and and easy package for end users to install.
>
>  An example of the C++ code I'm trying to emulate is at
> http://perrygeo.net/download/hillshade.html . Does anyone have any
> tips or examples out there? Where should I start researching this?
>
> --
> Matthew T. Perry
> http://www.perrygeo.net
> _______________________________________________
> Numpy-discussion mailing list
> Numpy-discussion@scipy.org
> http://projects.scipy.org/mailman/listinfo/numpy-discussion
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://projects.scipy.org/pipermail/numpy-discussion/attachments/20071125/d77069fc/attachment.html 


More information about the Numpy-discussion mailing list