memory leak problem with arrays

[sonjaa]

Carl Banks wrote:
> sonjaa wrote:
> > I've created a cellular automata program in python with the numpy array
> > extensions. After each cycle/iteration the memory used to examine and
> > change the array as determined by the transition rules is never freed.
>
> Are you aware that slicing shares memory?  For example, say you defined
> a grid to do the automata calculations on, like this:
>
> grid = numpy.zeros([1000,1000])
>
> And then, after running it, you took a tiny slice as a region of
> interest, for example:
>
> roi = grid[10:20,10:20]
>
> Then deleted grid:
>
> del grid
>
> Then stored roi somewhere, for example:
>
> run_results.append(roi)
>
> If you do this, the memory for the original grid won't get freed.
> Although grid was deleted, roi still contains a reference to the whole
> 1000x1000 array, even though it's only a tiny slice of it.  Your poorly
> worded description--no offense--of what you did suggests that this is a
> possibility in your case.  I recommend you try to create a new array
> out of any slices you make, like this (but ONLY if the slice doesn't
> depend on the memory being shared):
>
> roi = numpy.array(grid[10:20,10:20])
>
> This time, when you del grid, there is no object left referencing the
> array data, so it'll be freed.
>
> This might not be your problem.  Details are important when asking
> questions, and so far you've only given us enough to speculate with.
>
> Carl Banks

I believe I understand your post. I don't think I was slicing the
array, I was only changing the values of the array.

I will try your suggestion and let you know how it goes

thanks
Sonja