ntpviz - Don't plot a line during data absence

[Gary E. Miller]

Yo Eric!

On Sun, 23 Oct 2016 12:44:16 -0400
"Eric S. Raymond" <esr at thyrsus.com> wrote:

> Jason Azze <jason at azze.org>:
> > Whether or not it is worth a 10% slowdown is certainly debatable.  
> 
> Let's step back a bit.  Why is it important for ntpviz to be fast?

We already discussed this.  The load on a RasPi distorts the timing
so badly that it shows up on the ntpizv plots.  The Heisenberg Uncertainty
Principle in action: Mmasuring distorts the thing being measured.

Look at the spikes in the red line on the first graph here:

    https://pi4.rellim.com/day/

Each one of those is ntpviz running.  When ntpvis runs faster (finishes
in less time) the spikes get smaller.  The spikes used to me much, much,
bigger.

> I can see why it's important for ntpviz to use as few processor clocks
> as possible, in order to avoid causing artifacts in the data.  Is that
> the same issue?

Yes, plus it is a lot easier to debug a task that takes 36 seconds versus
one that takes 5 minutes.  Yes, it has a lot more feater now and is
still that much faster.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
	gem at rellim.com  Tel:+1 541 382 8588
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