[rrd-users] Local maximum and minimum

[Philip Gwyn]

Hello,

I have a 1-wire setup in my attic. I log temperature and humidity and
generate daily/weekly/monthly graphs. I use a modified temps.pl from
Thierry Hugue.

What I would very much like is to graph the local maximum and minimum
temperature. This would be roughly the maximum and minimum over a 24
hour period. The MAXIMUM and MINIMUM operators don't do what I want -
they find the max for the entire period.

Is this at all possible with RRD graphs? Or do I have to create another
data set and calculate it by hand?

-Philip

[Simon Hobson]

Post by Philip Gwyn
Hello,
I have a 1-wire setup in my attic. I log temperature and humidity and generate daily/weekly/monthly graphs. I use a modified temps.pl from Thierry Hugue.
What I would very much like is to graph the local maximum and minimum temperature. This would be roughly the maximum and minimum over a 24 hour period. The MAXIMUM and MINIMUM operators don't do what I want - they find the max for the entire period.

If you have a 24 hours consolidation for MAX and another for MIN, then that will contain values for max and min per day*. You can then graph that and get a graph of min/max by day. You may have to specify the consolidation when graphing if you have other min & max consolidations.

* Where "day" is a 24 hour period starting at midnight UTC. It will not be midnight to midnight if your local timezone isn't UTC.