Graph Utils (Open-Source)

Jimmy Hess mysidia at gmail.com
Sun Feb 20 22:45:02 CST 2011


On Fri, Feb 18, 2011 at 1:13 PM, Max Pierson <nmaxpierson at gmail.com> wrote:
> Anyone out there using something other than rrdtool for creating graphs?? I
> have a project that will need a trend taken, and unfortunately rrdtool
> doesn't fit the bill. All of the scripting, data collection,
> database archival, etc will be custom written or is already done (with some
> hacks of course :). So really what i'm looking for is something along the
> lines of GNUplot. Has anyone used it before and would like to share

I haven't heard of gnuplot used often with other software as a framework
for graphing/visualizations. For simple visualizations,  I think usually a
'native'  framework/API is preferred, e.g. JGraph for java apps.

I suspect one reason gnuplot is not used as widely as it could be otherwise
is, its  licensing is not as  "friendly" as other graphics frameworks.
gnuplot license is GPL incompatible and does not seem to even fully meet
the open source definition,

Because redistributing complete modified source code of gnuplot itself
is not allowed by the license;  a clear reading of gnuplot license suggests
only patches, unmodified source code, can be freely redistributed,
redistributed binaries based on modified source have special rules).


Aside from that caveat,  which most likely does not normally impair private
use by a network operator: gnuplot is a really good tool.
If you need to paint a bunch of  arbitrary X and Y values   on a graph from
an input file or based on simple equations,   gnuplot will happily
oblige; it can
handle chart types  rrdtool cannot, and you have more direct control of output.

If you want some 3D / surface graphs, RRDTool won't do it, anyways.
Gnuplot's less expensive
than Matlab / Maple.

You can even set terminal type to "dumb" in gnuplot, and generate some fancy
ASCII art graphs on stdout.


In regards to scalability...

About the millions of rows... err..
Try plotting a test dataset with 500 million datapoints.    Chances
are gnuplot won't
necessarily scale that well either, and you need some method to be
selective of which rows are
provided as input to the plotting framework, in that case.

If you have a  million datapoints on your X axis,  each X position is
smaller than  1/1000 of
a display pixel   (on a graph that fits on a display at say  1920x1080);
displaying such high resolution of all datapoints at once on the
unzoomed graph is beyond
the display hardware capabilitiy.

there should normally be some form of averaging / smoothing /
"selection of points"  contemplated,
if the dataset is huge

> experiences?? Seems like it will be able to my plot data accordingly, but
> wanted to see if there were any other popular tools I've yet to come across.
>
> (Open-Source only please)

--
-JH




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