Hi all,<br><br>I was browsing the lists archives from 2003 in search for an implementation of Rate Of Change calculated on <br>a GAUGE DS.<br>what i found is:<br><a href="https://lists.oetiker.ch/pipermail/rrd-users/2003-November/007513.html">https://lists.oetiker.ch/pipermail/rrd-users/2003-November/007513.html</a><br>
<br>i'm trying to figure out the best logical interpretation of ROC calculated over datapoints for several timeframes<br>(day,week, etc). my assumption is that if calculated correctly the number returned by the ROC would <br>
"trigger" inspecting the graphs visually for something wrong. (for example a ROC of 8 for a UPS load <br>or a temperature graph means something ugly is happening down there, and a normal ROC would be a number that <br>
heads as close to 0 (zero) value )<br><br>following the discussion in 2003:<br><br>VDEF:first=loadpct,FIRST<br>CDEF:oldvalue=TIME,POP,loadpct<br>CDEF:oldtime=loadpct,POP,TIME<br>CDEF:roc=loadpct,PREV(oldvalue),-,TIME,PREV(oldtime),-,/<br>
<br>printing out the result (on the graph for now)<br><br>GPRINT:roc:AVERAGE:Average ROC (Rate Of Change): %2.6lf"<br><br>the questions are:<br><br>- roc CDEFs results are available as an internal collection of values that are "willing" to be consolidated<br>
by AVERAGE,MIN,MAX,LAST functions. I didn't found any explanations for the AVERAGE<br>consolidating function - is it an arithmetical sum ? e.g. roc1+roc2+roc3 / 3<br><br>- is there another way of calculating over the CDEFs results - e.g. my own consolidation function - sum of square values for example<br>
(i suspect that using the AVERAGE function is misleading the results to 0) <br><br><br>I might have taken the wrong path. if anyone is statistically freak enough and willing to guide i'm all ears.<br>thanks in advance for your support<br>
<br><br>Marius Rugan<br>--------------------<br><br><br><br>