[rrd-users] Combining Multi-RRD Datapoints in Graph

[William R. Lorenz]

Hi Alex and friends,

On Fri, 13 Feb 2009, Alex van den Bogaerdt wrote:

>> 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?

> CDEF:result=source1,source2,source3,3,AVG

That CDEF function (as well as the similar add and divide averaging in 
CDEF notation) works great!  I gather the 'AVG' function does the exact 
same, as I see from the graphs.  In any case, this works perfectly.

Thanks so much,


-- 
William R. Lorenz