[rrd-developers] Output Bug: Problems w/ Y-Axis Units

[Tobias Oetiker]

Hi Casey,

Yesterday Casey McGinty wrote:

> Well, I realize that this type of "auto" layout is not trivial in the
> slightest. If I have a chance I may look into it. My first goal was to
> confirm that I wasn't missing some obvious solution in the command-line
> options.
>
> The reason I'm using the alt- methods is because I want to get a zoomed in
> view of my data. The default methods would generate a scale from 10 to 20,
> which for my data basically become a flat line. For my use case, I'm very
> interested in seeing if the line is trending up or down. So for example, a
> difference of 0.05 +/- on the graph is important to be able to see.

one feature that might help in your case which is curently missing
would be provide full user control over the yaxis, so that you
could force your exact precision and grid ... the yaxis config
allows most, but not the precision of the y axis label ...


cheers
tobi


> On Wed, Jul 7, 2010 at 8:13 PM, Tobias Oetiker <tobi at oetiker.ch> wrote:
>
> > Hi Casey,
> >
> > auto scaling is tough ... note that alt-y-grid and alt-autoscale
> > are two independent 'fixes'. Used together, they can produce rather
> > interesting results ... the two instances of 13 in the graph come
> > from the fact that one of the two insist on putting at least two
> > labels to the graph .. that they are both '13' is because the
> > difference between the two is > 1
> >
> > I still claim that my original algorithm (the thing you get without
> > the --alt* options when you just run rrdtool) is the most robust
> > one ... :-) but, by all means, if you see ways to generically
> > improve autoscaling, or add another alt-* algorithm, I would be
> > most interested in your contributions !
> >
> > cheers
> > tobi
> >
> > Yesterday Casey McGinty wrote:
> >
> > > I sent this to the users list, but didn't get any response. The code
> > below
> > > creates some weirdness on the Y-axis. Can I just force rrdgraph to output
> > > unit labels with 1 decimal place. Right now the graph gives me two
> > labeled
> > > lines, both are "13".
> > >
> > > ---------- Forwarded message ----------
> > > From: Casey McGinty <casey.mcginty at gmail.com>
> > > Date: Tue, Jul 6, 2010 at 8:37 PM
> > > Subject: Problems w/ Y-Axis Units
> > > To: rrd-users at lists.oetiker.ch
> > >
> > >
> > > Hi,
> > >
> > > Can someone show me how to get a better Y-axis on this graph? It would be
> > > nice if it could indicate the first decimal value. I know --rigid will
> > > adjust the range enough to fix it, but I like having a little padding on
> > the
> > > top and bottom. I'm running RRDtool 1.3.8
> > >
> > > rrdtool create test.rrd \
> > >    --step 36000\
> > >    --start 1278216000\
> > >    DS:test:GAUGE:36000:U:U \
> > >    RRA:AVERAGE:0:1:450
> > >
> > > rrdtool update test.rrd 1278216000:1.2995109312e+01
> > > rrdtool update test.rrd 1278252000:1.2386894574e+01
> > > rrdtool update test.rrd 1278288000:1.2756351457e+01
> > > rrdtool update test.rrd 1278324000:1.2922753446e+01
> > > rrdtool update test.rrd 1278360000:1.2355706091e+01
> > > rrdtool update test.rrd 1278396000:1.3136786020e+01
> > > rrdtool update test.rrd 1278432000:1.2281093692e+01
> > > rrdtool update test.rrd 1278468000:1.2874299159e+01
> > >
> > > rrdtool graph test.png --start 1262304000 --end 1278468000 \
> > >         --alt-autoscale \
> > >         --alt-y-grid \
> > >         --width 450 \
> > >         --height 125 \
> > >         DEF:test=test.rrd:test:AVERAGE \
> > >         LINE1:test#FF0000:test
> > >
> >
> > --
> > Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
> > http://it.oetiker.ch tobi at oetiker.ch ++41 62 775 9902 / sb: -9900
> >
>

-- 
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
http://it.oetiker.ch tobi at oetiker.ch ++41 62 775 9902 / sb: -9900