----- Original Message ----- From: "William R. Lorenz" <[email protected]> To: <[email protected]> Sent: Friday, February 13, 2009 2:19 PM Subject: [rrd-users] Combining Multi-RRD Datapoints in Graph
> Hi, > > I'm looking to take 2-4 unique RRD files that plot the same data from > different perspectives (i.e. temperature readings from four different > sensors) and average all the data points together into one graph line. > > Is there a CDEF, VDEF, or other such function that will allow me to > average more than one data source together for this rrdgraph purpose? > > If someone could point me to the applicable section of documentation > and/or has an example, I'd be very appreciative. Thanks, in advance. Sounds like you need to use CDEF AVG. See http://oss.oetiker.ch/rrdtool/doc/rrdgraph_rpn.en.html and look for the AVG function. CDEF:result=source1,source2,source3,3,AVG After you've succesfully averaged the temperatures into one temperature, you have your line. And you could then combine it with VDEF AVERAGE to print the average of those averages to get the average of all sources over all of the displayed time. VDEF:average=result,AVERAGE GPRINT:average:%6.2lf (or, without the VDEF: GPRINT:result:AVERAGE:%6.2lf) _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
