Can't exponentiate zero in NumPy
rpm at wag.caltech.edu
Mon Sep 9 17:39:48 CEST 2002
I found out more about this problem, and I'm still hoping that someone
can suggest a good fix.
The problem comes when I take a power of a NumPy array that has very
small values in it:
>>> from Numeric import *
>>> a = zeros(3,Float)
array([0., 0., 0.])
>>> a = 1.e-310
Traceback (most recent call last):
File "<stdin>", line 1, in ?
OverflowError: math range error
This crashes on Linux, but not on Mac OS X.
Is this a bug or a feature?
If it's a feature (which it might be), can someone offer a one-line
workaround? What I would like to do is set everything below a small
value (say 1.e-16) to zero. Obviously,
>>> for i in range(len(a)): if a[i] < 1.e-16: a[i] = 0
or something like it should work, but it will also be slow, and I was
hoping that one of the Numeric UFuncs might do the same thing more
Thanks in advance for any help anyone can offer.
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