Hi,
I've just tried to implement a "moving average" with graph, and it seems to work pretty nicely. I got the idea from how cisco is doing average load calculations http://www.cisco.com/warp/public/66/3.html This allows you to smooth spikes on graphs, fill in gaps in missing data, and add a "trend" lines to your graphs. By playing with weight factor you can nearly any "smoothness" desired. (hope I just didn't reinvent a wheel ;) new-mavg = ( (last-mavg - datasample) * weight + datasample weight=0.983 rrdtool graph $png -a PNG \ -h 400 \ -w 1000 \ --alt-y-grid \ --base 1000 \ -s -7week \ DEF:max=$rrdfile:ds1:MAX \ CDEF:inp2=max,UN,1,max,IF \ CDEF:mavg=PREV,UN,inp2,PREV,IF,inp2,-,$weight,*,inp2,+ \ "LINE1:inp2#FF0000:Max values\n" \ "LINE3:mavg#0000FF:Moving average, weight $weight" > From: Phil Henningsen <[EMAIL PROTECTED]> > > I have an RRDatabase that saves five ABSOLUTE variables (MIN, MAX & > AVERAGE) with readings taken at 5 minute intervals. Two of the variables > are "sparse and bunched". For example, the 6 readings over 30 minutes > might look like: 0, 10, 0, 12, 2, 8. > > This causes the "two day" chart (where the horizontal grid lines are 1 hour > apart) to look like a seismograph during an earthquake. That is, the lines > are very jagged over a wide range. > > Is there any way, while graphing, that I can use an average "as if" it were > sampled over a longer interval, thereby smoothing the graph? That is, in > the example above, the total over 30 minutes is 32, and I would like the > graph to treat it as if each of the 6 readings were 5.333 or at a rate of > 1.0666 per minute. > > If I look at a two day interval way back in history, say 6 months ago, the > charts have the "smoothed" effect that I would like to achieve in the > current period. > > Thanks for your assistance. ------------------------------------ Andres Kroonmaa <[EMAIL PROTECTED]> Delfi Online Tel: 6501 731, Fax: 6501 708 Pärnu mnt. 158, Tallinn, 11317 Estonia -- Unsubscribe mailto:[EMAIL PROTECTED] Help mailto:[EMAIL PROTECTED] Archive http://www.ee.ethz.ch/~slist/rrd-users WebAdmin http://www.ee.ethz.ch/~slist/lsg2.cgi
