Thanks for the clarification... I'm still not sure that I think the 0-shift should be included when using a negative count but that's likely personal preference and, as you say, the explicit list is always available anyway.
Maybe it should also allow the use of 0 to mean a single 0-shift -- ie 0,x,PREDICT to be the same as 0,1,x,PREDICT Of course, currently with the negative setup not including n, this is also the same as s,-1,x,PREDICT for any value of s, which is a bit pointless and the main reason I felt something was amiss. I have a paragraph written up on this behaviour for the RRDTool book I'm working on (yes! it lives! like a zombie it pulls itself from the 2-year-old grave...) so I'll email this to Tobi for inclusion in the online manual if he wants. As for a predict_median and predict_percentile -- as you say, they could be very CPU-expensive, and also if you're going that far it's likely that you'd just set up a few HW RRAs to use instead. Still, it never hurts to have more tools in your toolbox... If we're adding new operations to the RPN, my choice would be for ROL and ROR (rotate top 3 stack items) and some date calculations (given an epoch time, extract day of week, hour of day, etc in local timezone). Maybe I'll download the latest dev snapshot and see what I can do. Steve Steve Shipway University of Auckland ITS UNIX Systems Design Lead [email protected] Ph: +64 9 373 7599 ext 86487 _______________________________________________ rrd-developers mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-developers
