<div class="gmail_quote">Sorry to answer my own post, but it may help some other searching soul.<br><br>On Thu, Mar 10, 2011 at 8:44 AM, Chris Nighswonger <span dir="ltr"><<a href="mailto:cnighswonger@foundations.edu">cnighswonger@foundations.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">I'm wondering if this is possible with rrdtool:<br><br>I have a sensor which is logged once every 30 seconds.<br>
<br>I would like to produce a graph on which each point represents a 15 min average of the sampled data.<br>
<br>Here is the caveat: The graph should have as many points as there are 30 second data points with each point representing the average of the previous 15 minutes worth of data points. So a sort of "running average" if you will.<br>
<br></blockquote><div><br>This is called a Moving Average in statistics. (<a href="http://en.wikipedia.org/wiki/Moving_average">http://en.wikipedia.org/wiki/Moving_average</a>)<br> </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
I'm guessing some DEF or CDEF magic will be needed to do this.... but I'm no statistics guru. :-)<br></blockquote><br>The magic is already there with the RPN notation 'TREND' and 'TRENDNAN.' (<a href="http://oss.oetiker.ch/rrdtool/doc/rrdgraph_rpn.en.html#Set%20Operations">http://oss.oetiker.ch/rrdtool/doc/rrdgraph_rpn.en.html#Set%20Operations</a>)<br>
<br>Kudos to the devs for this super tool!<br><br>Kind Regards,<br>Chris<br></div>