[SciPy-user] Floating-point summation

Nils Wagner nwagner at mecha.uni-stuttgart.de
Tue Dec 14 05:42:55 CST 2004


Robert Kern wrote:

> Nils Wagner wrote:
>
>> Hi all,
>>
>> Afaik scipy's sum(x) relies on Numeric's sum implementation.
>> However, the result of the actual implementation of sum(x) may be 
>> inaccurate
>> as illustrated in the small example (sum.py).
>>
>> Any comment ?
>
>
> Implement kahan_sum() in C for all types, and I'll stick it in 
> scipy_base. I'm inclined to leave sum() as it is for performance reasons.
>
Unfortunately, I am not familiar with C, but I found a paper
by Evan Manning
 

*Manning, Evan, /Floating Point Summation/. C/C++ Users Journal 
<http://www.cuj.com/>, September 1996. *

http://alumnus.caltech.edu/~manning/
http://www.cuj.com/

Nils




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