numpy-discussion

[Numpy-discussion] memory leak in array

[<saa...@sf...>]

Hi

I'm new to programming in python and I hope that this is the problem.

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.
I've tried using "del" on every variable possible, but that hasn't
worked. I've read all the forums for helpful hints on what to do, but
nothing has worked so far. I've even tried the "python memory
verification" (beta) program, which did point to numpy.dtype and
numpy.ndarray as increasing objects, before the whole computer crashed.

I can supply the code if needed. I'm desperate because this is part of
my thesis, and if I can't get this fixed, I'll try another programming
language.

Update: I posted this message on the comp.lang.python forum and their 
response was to get the numbers of references with sys.getrefcount(obj). 
After doing this I see that iterative counters used to count occurrences 
and nested loop counters (ii & jj) as seen in the code example below are the
culprits with the worst ones over 1M:

		 for ii in xrange(0,40):	
		    for jj in xrange(0,20):
			try:
			    nc = y[a+ii,b+jj]
			except IndexError: nc = 0
			
			if nc == "1" or nc == "5":
			    news = news +1
			    if news == 100:
				break
			    else:
				pass
			    y[a+ii,b+jj] = 4
			else:
			    pass


The version of python I'm using is 2.4.3 and the version of NumPy is 0.9.8



thanks in advance
Sonja 

Re: [Numpy-discussion] memory leak in array

[Robert K. <rob...@gm...>]

saa...@sf... wrote:

> Update: I posted this message on the comp.lang.python forum and their 
> response was to get the numbers of references with sys.getrefcount(obj). 
> After doing this I see that iterative counters used to count occurrences 
> and nested loop counters (ii & jj) as seen in the code example below are the
> culprits with the worst ones over 1M:
> 
> 		 for ii in xrange(0,40):	
> 		    for jj in xrange(0,20):

Where are you getting this 1M figure? Is that supposed to mean "1 Megabyte of
memory"? Because they don't consume that much memory. In fact, all of the small
integers between -1 and 100, I believe (but certainly all of them in xrange(0,
40)) are shared. There is only one 0 object and only one 10 object, etc. That is
why their refcount is so high.

You're going down a dead end here.

> 			try:
> 			    nc = y[a+ii,b+jj]
> 			except IndexError: nc = 0
> 			
> 			if nc == "1" or nc == "5":

What is the dtype of y? You are testing for strings, but assigning integers.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
  -- Umberto Eco