[Numpy-discussion] python eats memory like the cookie monster eats cookies

[Niels Provos]

Good morning,

not sure if I got the right list, but I hope that somebody here will
be able to shed some light on a Python-related memory problem.  The
following code eats over >2GB of memory and fails with MemoyError
after just a few iterations.

def ZeroPadData(A, shape):
    a = Numeric.zeros(shape, 'w')
    a.savespace()

    for y in xrange(A.shape[0]):
        for x in xrange(A.shape[1]):
            a[y, x] = A[y, x]

    return a

def EatMemoryLikeTheCookieMonster(limit=10):
    A = Numeric.ones([1998, 3022])

    count = 0
    a = A
    while count < limit:
        print count
        count += 1

        a = ZeroPadData(a, [2048, 4096])

        b = fft2(a)
        b = ifft2(b)

        a = b[:1998,:3022].real

EatMemoryLikeTheCookieMonster()

This is for Python 2.4.3 on Mac OS X 10.4.8 (intel) using SciPy 0.5.2.

If anyone could enlighten me about what I am doing wrong, I would very
much appreciate it.

Thank you,
 Niels.