Last comment: Let's not forget that many monitors repaint well less than 100 Hz!
---- [email protected] wrote: > > > Hi all, > > Just to add to this, you would be much better off displaying > 'high frequency' data in a more usable format. So instead of trying > to update a gauge every 1/100th of a second, show the min/max > value range for the last 2sec with a 1/10th of a sec (weighted) > average as the 'current' value. Update that a couple times a > second and you will get all the information anyone needs. > > Ronan Oger wrote: > > > Guys... > > > > Don't push your SVG update rates too high. In my opinion there is nothing > > to > > be gained in going past 20Hz (20 updates/second), and plenty to be gained > > from staying below 10Hz (10 per second). > > > > No matter what you intend to do, you need to allow for the transport layer. > > A > > 100-Hz update rate is meaningless if you have a 100ms lag When you do > > traceroute tests, you will see that the delays you can expect on the > > internet > > are 0.3 seconds for round-tripping.... With that kind of performance, you > > are > > seriously wasting your time if you are sampling at 10x or 20x your lag... > > Might as well go with 5-20Hz.... That's the best you can expect to need if > > you use tcp systems. > > > > A comparison that may be useful to you guys... I've been doing a lot of > > monitoring systems work using the Micromuse Netcool messaging > > infrastructure. > > For larger applications, you end up needing to send your signals to a > > concentrator of some kind, even if it is to allow for scalability and > > auditing purposes... With Netcool, we find ourselves working with a > > 2-second > > lag due to the 2-step forwarding (alert event->central bus, bus->monitoring > > client). > > > > The point in the end is that you will be hard pressed, in my opinion, to > > require anything like 100Hz update rates. > > > > Finally, consider the scanning rate of your monitor. There is no point in > > doubling the scanning rate of your monitor, and even the best PC struggles > > to > > get past 100Hz updates. > > > > While it's true that instrumentation sampling rates may have high speed > > requirements for such things as closed-loop control, human beings are far > > slower with this stuff, and there are plenty of reasons why there is no > > need > > to go past 20-Hz when showing input to the user. > > > > I propose to you that the key performance criteria in all of our real-time > > GUI > > tools is not refresh rate but transmission speed. > > > > Ronan > > > > On Tuesday 11 January 2005 12:08, Rick Bullotta wrote: > > > >>I think the "bottom line" is that a solution involving ASV, inside a > >>browser, with a real-time 100Hz update, is highly unlikely, but custom > >>solutions using Batik, SharpVectorGraphics, or Mobiform may be possible. > >> > >>---- [email protected] wrote: > >> > >>>Hi, > >>> > >>> > >>>>You could probably feed that with a streaming feed over a socket, > >>>>but to the best of my knowledge there is no way to do this in > >>>>JavaScript. > >>> > >>>In Batik it works just fine. I have partially impl. the SVG1.2 Sockets > >>>using JavaScript in Batik. > >>> > >>>see http://jan.kollhof.net/projects/svg/playground/ > >>>or the SVG IRC client here: > >>>http://jan.kollhof.net/projects/svg/examples/index.xhtml > >>>they only work in Batik. > >>> > >>> > >>> > >>> > >>>Jan > >>> > >>> > >>> > >>> > >>> > >>>----- > >>>To unsubscribe send a message to: > >>>[EMAIL PROTECTED] -or- > >>>visit http://groups.yahoo.com/group/svg-developers and click "edit my > >>>membership" ---- > >>>Yahoo! Groups Links > >> > >>----- > >>To unsubscribe send a message to: > >>[EMAIL PROTECTED] -or- > >>visit http://groups.yahoo.com/group/svg-developers and click "edit my > >>membership" ---- > >>Yahoo! Groups Links > >> > >> > >> > > > > > > > > ----- > To unsubscribe send a message to: [EMAIL PROTECTED] > -or- > visit http://groups.yahoo.com/group/svg-developers and click "edit my > membership" > ---- > Yahoo! Groups Links > > > > > > > > > ----- To unsubscribe send a message to: [EMAIL PROTECTED] -or- visit http://groups.yahoo.com/group/svg-developers and click "edit my membership" ---- Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/svg-developers/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
