[Xapian-discuss] Re: Xapian-discuss Digest, Vol 40, Issue 15

[Emmanuel Eckard]

These doubles will often amount to probabilities, though to stay generic, it 
would be safer to assume that they do not necessarily.

I understand that fitting Xapian with a generic interface for research goes 
somewhat against its optimisations for retrieval speed. I don't know in which 
measure it could be possible to offer these features as supplementary 
packages or as configure options.

> If the doubles are only used to store probabilities and thus all
> the doubles are in the range 0.0 <= x <= 1.0, then you may be
> able to re-use integers and interpret them as fixed-point
> rather than floating-point.
>
> Even a 32-bit integer gets you somewhere around 9+ digits of
> precision as long as you're in the 0 to 1 range.
>
> That may be a space/time tradeoff though, unless you could
> implement all the algorithms to use integer math rather than
> floating point.

-- 
Emmanuel Eckard                              
Artificial Intelligence Laboratory, EPFL
LIA/IC 1014 Ecublens, Suisse                     
+41 21 693 66 97       

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