[Qt-interest] Qt Charting Component - Feedback Request

[Peter M. Groen]

Markus et al.

By implementing a graph widget in a MVC-like pattern, I think this problem
can be solved. Don't have the answer (yet) but my gut feeling tells me
this shouldn't be hard to do... Something like the MVC-pattern Trolltech
used in their data-view...  (QAbstractItemModel).

Regards,
-- 
Open Systems Development
Peter M. Groen

Markus Franke wrote:
> Dear all,
>
> Syam Krishnan wrote:
>
>> I'm very much interested in a good charting component. We've been trying
>
>> out Qwt, but it seems to have some performance problems when used with
>> larger changing datasets.
>> Our requirement often is plotting of continuous data. i.e. a new data
>> point is available every 100 or 200 ms. Adding these points to the plot
>> should be as light-weight an operation as possible. As far as I can see,
>
>> the current Qwt implementation requires copying the entire point list
>> again and re-plotting from the beginning. This consumes a lot of CPU.
>> I'd love to see an implementation where incremental plotting is
> super-fast.
>
> same with us. We're looking for a charting class which is able to
> efficiently plot data which continously changes over time. Cycle times are
> also around 50 to 100 milliseconds. Right now we do everything by
> ourselves based on QWidget. However for a graph like a sinus wave which
> amplitude continuously changes over time it's always needed to repaint the
> whole waveform once a new data point is appended to the end. The whole
> graphic needs to be shifted to the left as we only print the values of the
> last few seconds.
>
> Is there a way to efficiently plot this kind of data with your charting
> class?
>
> Best regards,
> Markus Franke
>
>
> "Disclaimer: This message is intended only for the use of the individual
> or entity to
> which it is addressed and may contain information which is privileged,
> confidential, proprietary,
> or exempt from disclosure under applicable law. If you are not the
> intended recipient or the person
> responsible for delivering the message to the intended recipient, you are
> strictly prohibited from
> disclosing, distributing, copying, or in any way using this message. If
> you have received this
> communication in error, please notify the sender and destroy and delete
> any copies you may have
> received."_______________________________________________
> Qt-interest mailing list
> Qt-interest at qt.nokia.com
> http://lists.qt.nokia.com/mailman/listinfo/qt-interest
>