Re: Non-contaminating emptyness indicator

[Dr. Alexander Klein]

Am 06.07.2013 um 17:54 schrieb CdeMills:

> I have an application producing lots of data, collating everything into a
> matrix. Sometimes one entry is missing: I would like to fill it with
> something preserving the ability for statistical functions to return
> something meaningfull.

Hello,

I think we already had this topic once or twice on the old Octave-Forge list, 
and if I recall correctly, the best current practice seems to be to use the 
NaN-Toolbox from Octave-Forge which solves this very problem by using vanilla 
NaNs as the "emptiness indicator".

I vaguely remember that distinguishing a NA from a NaN includes a significant 
performance penalty, because you have to analyse the exact pattern of bits.

        Alex

-- 
Dr. Alexander Klein, Diplom-Mathematiker
TransMIT-Projektbereich für Mathematische Analysen und Feld-Simulationen
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D-35394 Gießen

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