Nathan Scott wrote:
Hi Greg!
:)
http://en.wikipedia.org/wiki/Spectrogram
I was wondering if there was a feasible way to display such a chart in
kmchart, assuming the existance of either a) a single counter metric
with multiple instances representing histogram buckets, or b) multiple
metrics representing histogram buckets.
We cannot do this *today* but this is the kind of thing I'm hoping to add
support for in the next big iteration of km^Wpmchart (kmchart just a shell
script nowadays, btw).
pmchart uses Qwt for its graphing. Qwt already supports spectrograms:
e.g. http://qwt.sourceforge.net/spectrogramscreenshots.html
... so, lucky us!, we even have code readily available to provide this.
Excellent. I notice the widget even does iso$foo lines.
The trickier parts of implementing it will be:
- extra UI work will be needed for creating/editing such charts - not just
the one metric per plot now,
Yep, that's kinda tricky.
and specifying the colour map would need some
design thought & new code
The only thing you'd ever need the user to control would a single colour
tuple. To generate all the others, convert the base colour tuple to HSV
and vary the V from 0.0 to 1.0. This gets you effectively a tinted
greyscale.
Or you could use the "thermal" gradient in those Qwt examples, that
looks just fine if rather colourful.
- config file support for saving/loading views for these more "interesting"
chart types. This is well underway, [...]
Yay.
--
Greg.
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