[Numpy-discussion] The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

[Rick Muller]

Help! I'm having a problem in searching through the *elements* if a 2d
array. I have a loop over a numpy array:

    n,m = G.shape
    print n,m
    for i in xrange(n):
        for j in xrange(m):
            print type(G), type(G[i,j]), type(float(G[i,j]))
            g = float(abs(G[i,j]))
            if g < cut:
                print i,j,G[i,j]

However, I'm getting the error message:

    The truth value of an array with more than one element is ambiguous. Use
a.any() or a.all()

despite the fact that I'm not computing a truth value of an array. I'd like
to just compare to G[i,j] or abs(G[i,j]), which should be a *single* value,
and *not* an array. I even call 'float' here to make sure that I cast this
to a normal python float. But I still get this error message.

At this point, I suspect that I'm doing something dumb, rather than
discovering some unique bug in numpy. Can anyone help me out?

-- 
Rick Muller
rpmuller at gmail.com
505-750-7557
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