[rrd-users] Sup-Sample Aggregate Functions?

Tim Soderstrom tim at moocowproductions.org
Thu Apr 12 19:20:41 CEST 2007

Hi All!

I was curious as to if it was possible to create a graph that contains a 
sub-sample aggregate. What I am trying to do is basically smooth out a 
series of points to produce a sort of trend. This actually works well 
but the problem is that I am using a step-size of 2 seconds and am only 
recording data for a short period of time (a few minutes). As a result, 
the graphs look very blocky since you can see jaggedness. Here are some 


You can see the Trend (using HWPREDICT here) and the Average (using the 
TREND VDEF) come close, but I really want a spline-based smoothing or 
something along those lines.

Something, for instance, similar to this:


Really, I don't care about the actual datapoints. I care about making a 
smooth looking graph that is an estimate of the actual datapoints. I 
checked #rrdtool and was told it was not possible with the standard 
version of rrdtool. Anyone have any ideas on how I could augment rrdtool 
for this or had another suggestion on what I could use?


Tim S.

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