[rrd-users] Calculation that is a bit over my head.

[Jan Johansson]

Hello!

 I would like o start with giving you a HUGE compliment for your answer. It is verbose, clearly written and quite frankly a joy to read!

Thank you!

>DEF:onpercent=/opt/Krokopool/RRDDatabases/Styrning_Varmare.rrd:Styrning_Varmar>e:AVERAGE
> CDEF:ontime=onpercent,86400,*,3600,/
> CDEF:totpower=ontime,3,*

Ah, yes, I have finally gotten my "Eureka-moment" about CDEF now i think. 

I do not suppose there is any "magic" subsitution for replacing (in this case) 86400 with "The number of seconds between -s and -e params?


>There is also (IIRC) the total function, so "VDEF:ontime,3,*,TOTAL" to get a single value >that you can later [g]print.

Is there any way to use print without generating a graph? The docs seem suggest that "-" supresses all output tho, so I am guessing "No"?


>Also, I'd suggest not using terms like "now" and "now - 1 day". Better to specify start and >end times which are integer multiples of the consolidated step period you intend to use. >Eg, if you are working with a 300s copnsolidation, then start and end should be an integer >multiple of 300; for 1/2 hour consolidations it would be 1800 and so on. And make sure >that end-start = pixels*step time so that the data isn't further processed to fit your >graph.

This paragraph is extremely informative. Again, thanks! (But for this, I will mostly just use the timespan of "00:00" to just do the calcs for the previous day.