[rrd-developers] NAN-safe ADD
tobi at oetiker.ch
Thu Mar 6 06:48:32 CET 2008
> On Thu, Mar 06, 2008 at 01:44:30AM +0100, Timo Stripf wrote:
> > Hello,
> > i've implemented a nan-safe add operator (ADDNAN) into rrd. I used it
> > to add several incomplete graphs.
> > NaN + NaN => NaN
> > x + NaN => x
> > NaN + y => y
> > x + y => x + y
> Quite often 'NaN' does not mean 'nothing'. In many cases substituting
> the average of the two neighbours (not direct neighbours per se) would
> make more sense.
> At the very least I think this feature deserves more documentation than
> just a line or two.
How about doing this explicitly:
then the effort for doing it has some relationship to the 'danger'
of the operation.
or if you insist to make this simpler, how about implementing a
NANTOZERO operator ?
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten
http://it.oetiker.ch tobi at oetiker.ch ++41 62 213 9902
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