numpy-discussion

[Numpy-discussion] underflow array([2.9e-131])**3

[Jean-Bernard A. <jb...@ph...>]

Hey Numpy people!

Do anyone know how to disable underflow exception errors in Numeric?

I have a lot of these in my code. It is now a very important problem in my
calculations. The only solution I see is to make a for loop and make the
arithmetic in python instead of Numeric.

Thanks for your help,

	Jean-Bernard

Python 2.0 (#9, Feb  2 2001, 12:17:02) 
[GCC 2.95.2 19991024 (release)] on linux2
Type "copyright", "credits" or "license" for more information.
Hello from .pythonrc.py
>>> import Numeric
>>> Numeric.__version__
'17.2.0'
>>> Numeric.array([2.9e-131])**3
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
OverflowError: math range error
>>> 2.9e-131**3
0.0

Re: [Numpy-discussion] underflow array([2.9e-131])**3

[Konrad H. <hi...@cn...>]

> Do anyone know how to disable underflow exception errors in Numeric?

The problem is not in Numeric, it is the C library that decides
whether underflows should be considered errors or not. The Python
interpreter has some workarounds, but Numeric has not. I had the same
problems you describe under AIX, where I solved them by linking to a
different version of the math library. But I don't think there is
a platform-independent solution.

Konrad.
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