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From: White, G. <gr...@sl...> - 2010-08-22 22:15:22
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Right, as Ralph was pointing out, there is a difference between statistically reduced data that is then archived, raw data which is reduced by the archiver as part of the archiving process, and archived data which is reduced by the archive server as part of making a reply. I think common practice is to reduce data at the stage of archiving it - at least to record repeat counts of same valued data. Eg, if a PV's value doesn't change between archiver polls/monitor callbacks, we just increase the repeat count (and don't bother recording the times at which those same values were found). It's this "repeat count" that I included in my interface definition. So I'll add to the interface also a way to include what Bob wants - a way for the archiver to tell a client that what it recorded was itself reduced data, and the meta data of that reduction (eg Standard deviation). Cheers Greg On Jul 29, 2010, at 10:55 AM, Ralph Lange wrote: > On 29.07.2010 12:43, Dalesio, Leo wrote: >> >> Before going further with the proposal to filter, let's check the performance is actually network bound. >> --- imagine I want to look at one year of temperature variation. Computation over network bandwidth seems obvious. More importantly though, I would like to introduce the archiving of statistical samples - this would allow me to have my bpm fpga compute the statistical information on turn by turn data that I could then archive or study for errant behavoir. >> > > Note that in this case - the BPM FPGA calculates the statistical values - those values would simply be the raw archived numbers. > > Which is different from the proposal that had the statistics calculated by the archive retrieval daemon when sending binned data back to the client. > (Except that for your case - where the raw data are statistical values - the algorithm that calculates statistics on these when binning might have to be different.) > > Ralph > > ps. Please: send answers only to the mailing list, and configure your mail client to use the standard "> " quoting. > ------------------------------------------------------------------------------ > The Palm PDK Hot Apps Program offers developers who use the > Plug-In Development Kit to bring their C/C++ apps to Palm for a share > of $1 Million in cash or HP Products. Visit us here for more details: > http://p.sf.net/sfu/dev2dev-palm_______________________________________________ > Pvmanager-devel mailing list > Pvm...@li... > https://lists.sourceforge.net/lists/listinfo/pvmanager-devel |
