# [rrd-users] Re: graphing question

Chris Wilson chris at aidworld.org
Tue Jul 26 14:43:29 MEST 2005

```Hi again,

> > > I'm measuring temperature at regular intervals all day.  Graphing that is of course easy
> > > - but I'd also like to see a graph over e.g. 30days or longer indicating how many hours
> > > per day the temperature was above 24C.  (or some other arbitrary number).  How do I go

> I'm just an RRD beginner, but you could probably calculate and sum the
> number of hours over a certain time with an RPN expression and then
> graph that.
>
> I don't know the syntax, but something like "temperature 24 > 1 0 if
> sum" might do it. (equivalent to SUM(IF(temperature > 24,1,0)) in a
> bracketed meta-language).

See
http://people.ee.ethz.ch/~oetiker/webtools/rrdtool/doc/rrdgraph_rpn.en.html for details.

This might work:

CDEF:hoursover24deg=temperature,24,GT,1,0,IF,TOTAL

Cheers, Chris.
--
(aidworld) chris wilson | chief engineer (chris at aidworld.org)

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