[smokeping-users] Graph scale problem

[G.W. Haywood]

Hi Tobi,

On Tue, 29 Apr 2008, Tobias Oetiker wrote:

> Hi Dan,

Er, Ged. :)

> yes you did find a number of corner cases here .. the problem realy
> is what algorithm to use for the proper scaling. At the moment I
> only look at the median and then add some space on top of it. But
> maybe we should look at some other property ...
>
> look for the find_max function in Smokeping.pm to see what is
> presently being done ...

Er, findmax.  There's a findmin now too. :)

> as for the logarithm stuff, this is a user contributed feature
> which is not well integrated. I do all my work without it enabled,
> I guess it would need rather different settings to work well.

I've been fiddling about with it and I've come up with something that
Works For Me (TM).  Would you like me to send you the code?  It's just
a bunch of modifications to Smokeping.pm.  It's still in the prototype
stage and not really ready for the public, so I don't think I should
be making patches just yet but it might be useful to somebody.  Anyway
the logarithmic graph scales seem to work a bit better now:

http://www.jubileegroup.co.uk/JOS/misc/logarithmic_graphs.png

Basically I just look for the range in the data and scale the graph
limits so they're a few tens of percent wider than that.  The scale
factors are easily adjusted.  I have no idea what I've broken. :)
Next I was thinking of putting them in the configuration somewhere.

> For the upcomming ajax version of smoekping I imagine to have graph
> properties configurable interactively so that you can make a graph
> look right by hand once you have identified an interesting section.

Cool!  Would that propagate to the non-ajax graphs?

--

73,
Ged.