I think I might have gotten bumped off the list as I don't see my replies. Ondrej, hope this reaches you. While your data may have a step of 300 secs and you might even set the step size on the command line or even on the rrd datasource def this is not the step size used. The step used will be the number of seconds that can fit in one pixel. You can force the step by controlling the image resolution and the time range or just calculate the step knowing the image resolution and time range. In some of my scripts I force an image resolution of 4k so that step size can be 60 secs. This actually allows me to use the rate of change in a meaningful way. If my LSLSlope is 10Mb and my step is 60 that's 10Mb/min.
Inside RRD I calculate the stepwidth with the following. CDEF:c=var1,COUNT,EXC,POP --- The count of steps as a data set from 1 to end of chart CDEF:t=var1,TIME,EXC,POP --- time range of graph as a data set VDEF:tmin=t,MINIMUM --- starting time VDEF:tmax=t,MAXIMUM --- ending time VDEF:cmax=c,MAXIMUM --- count of steps plus one CDEF:s=var1,POP,tmax,tmin,-,cmax,1,-,/ --- data set of stepwidth, calculated from (end time - start time) / (count -1) VDEF:stepwith=s,MAXIMUM --- stepwidth as a single value Cannot do RPN on a VDEF so do the math into a dataset, then pull a value. Max or Min doesn't matter. Every value is the same. Inside RRD 1.5.4 there is a function STEPWIDTH. The width of the current step in seconds. This is a fairly recent version. You can use this to get the step size with fewer calculations. CDEF:step=var1,STEPWIDTH,EXC,POP VDEF:stepw=step,MAXIMUM Now if I could get some to tell me how to gprint this as Days:Hours:Mins:Secs. When I look at a one year graph I GPRINT the stepwidth on the graph but what is a step of 64.8k seconds? 7.5 days would be much more clear. That info combined with the slope of say 10GB tells me my rate of change is 10GB every week (roughly). Now if I could get seconds to scale like bytes do with SI units for time. -- View this message in context: http://rrd-mailinglists.937164.n2.nabble.com/Question-about-trend-line-tp7583077p7583108.html Sent from the RRDtool Users Mailinglist mailing list archive at Nabble.com. _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
