From: oetiker Date: Thu, 16 Aug 2007 07:31:53 +0000 (+0000) Subject: added holt winters example back into the examples documentation X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=c1f4d92a5b64793471b6a4ca78ec7fa71db18df9;p=rrdtool.git added holt winters example back into the examples documentation git-svn-id: svn://svn.oetiker.ch/rrdtool/trunk/program@1193 a5681a0c-68f1-0310-ab6d-d61299d08faa --- diff --git a/doc/rrdgraph_examples.pod b/doc/rrdgraph_examples.pod index 64e3840..7a6aba4 100644 --- a/doc/rrdgraph_examples.pod +++ b/doc/rrdgraph_examples.pod @@ -70,7 +70,7 @@ Note: the column titles have to be as wide as the columns Depending on your needs you can do this in two ways: -=over 4 +=over =item * @@ -121,6 +121,62 @@ Shift the data forward by one week (604800 seconds) AREA:lastweek#0000FF:Last\ week LINE1:thisweek#FF0000:This\ week +=head2 Aberrant Behaviour Detection + +If the specialized function B exist for aberrant behavior detection, they +can be used to generate the graph of a time series with confidence bands and +failures. + + rrdtool graph example.png \ + DEF:obs=monitor.rrd:ifOutOctets:AVERAGE \ + DEF:pred=monitor.rrd:ifOutOctets:HWPREDICT \ + DEF:dev=monitor.rrd:ifOutOctets:DEVPREDICT \ + DEF:fail=monitor.rrd:ifOutOctets:FAILURES \ + TICK:fail#ffffa0:1.0:"Failures\: Average bits out" \ + CDEF:scaledobs=obs,8,* \ + CDEF:upper=pred,dev,2,*,+ \ + CDEF:lower=pred,dev,2,*,- \ + CDEF:scaledupper=upper,8,* \ + CDEF:scaledlower=lower,8,* \ + LINE2:scaledobs#0000ff:"Average bits out" \ + LINE1:scaledupper#ff0000:"Upper Confidence Bound: Average bits out" \ + LINE1:scaledlower#ff0000:"Lower Confidence Bound: Average bits out" + +This example generates a graph of the data series in blue (LINE2 with the scaledobs +virtual data source), confidence bounds in red (scaledupper and scaledlower virtual +data sources), and potential failures (i.e. potential aberrant aberrant behavior) +marked by vertical yellow lines (the fail data source). + +The raw data comes from an AVERAGE B, the finest resolution of the observed +time series (one consolidated data point per primary data point). The predicted +(or smoothed) values are stored in the HWPREDICT B. The predicted deviations +(think standard deviation) values are stored in the DEVPREDICT B. Finally, +the FAILURES B contains indicators, with 1 denoting a potential failure. + +All of the data is rescaled to bits (instead of Octets) by multiplying by 8. +The confidence bounds are computed by an offset of 2 deviations both above +and below the predicted values (the CDEFs upper and lower). Vertical lines +indicated potential failures are graphed via the TICK graph element, which +converts non-zero values in an B into tick marks. Here an axis-fraction +argument of 1.0 means the tick marks span the entire y-axis, and hence become +vertical lines on the graph. + +The choice of 2 deviations (a scaling factor) matches the default used internally +by the FAILURES B. If the internal value is changed (see L), this +graphing command should be changed to be consistent. + +=head3 A note on data reduction: + +The B I command is designed to plot data at a specified temporal +resolution, regardless of the actually resolution of the data in the RRD file. +This can present a problem for the specialized consolidation functions which +maintain a one-to-one mapping between primary data points and consolidated +data points. If a graph insists on viewing the contents of these B on a +coarser temporal scale, the I command tries to do something intelligent, +but the confidence bands and failures no longer have the same meaning and may +be misleading. + + =head1 SEE ALSO L gives an overview of how B works.