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Re: Non-contaminating emptyness indicator
From: |
Dr. Alexander Klein |
Subject: |
Re: Non-contaminating emptyness indicator |
Date: |
Mon, 8 Jul 2013 13:31:46 +0200 |
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
Kerkrader Straße 3
D-35394 Gießen
http://www.transmit.de/zentren/tz.cfm?N=165