[vz-dev] line charts are wrong display style for "power" type data!
jh at plonk.de
Tue Jun 28 16:54:31 CEST 2011
Harald Koenig, 2011-06-28 14:00:
> for "power" style data you must not draw lines between measurement
> points as this gives totally wrong graphs (esp. for pulse
Which version do you use?
We changes that a while ago to horizontal lines. Here's what it looks
like in the current version:
> so: for every measurement point you should draw some line or
> rectangle with the area beyond that line/rect being propotional to
> the energy in that time interval (== power_value * delta_time). thus
Well, the energy is always the same for a given sensor, e.g. for sensors
with 2000 impulses/kWh it's 0.5Wh/impulse, but I think you already knew
We measure the time between two impulses and therefore get the average
power in the time interval between the two impulses, which is the height
of the line.
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