[Numpy-discussion] Re: [Matrix-SIG] An Experiment in code-cleanup.

skaller skaller at maxtal.com.au
Wed Feb 9 16:04:13 CST 2000


Konrad Hinsen wrote:
> 
> > silently). Consider a function
> >
> >       k0 = 100
> >       k = 99
> >       while k < k0:
> >               ..
> >               k0 = k
> >               k = ...
> >
> > which refines a calculation until the measure k stops decreasing.
> > This algorithm may terminate when k is a float, but _fail_ when
> > k is a double  -- the extra precision may cause the algorithm
> 
> I'd call this a buggy implementation. Convergence criteria should be
> explicit and not rely on the internal representation of data
> types. 

> If you care at all about portability, you shouldn't even think about
> this.

	But sometimes you DON'T care about portability.
Sometimes, you want the best result the architecture can support,
and so you need to perform a portable computation of an architecture
dependent value.

-- 
John (Max) Skaller, mailto:skaller at maxtal.com.au
10/1 Toxteth Rd Glebe NSW 2037 Australia voice: 61-2-9660-0850
homepage: http://www.maxtal.com.au/~skaller
download: ftp://ftp.cs.usyd.edu/au/jskaller




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