Planned maintenance has been done but it did not solve the problem. So work will continue on this and a new time for trying updates will be announced asap.

Qt Charting Component - Feedback request



  • bq. Do you mean like plotting time series of real-time data? If so then yes, this will be supported.

    Yes, that was what I was looking for.

    bq. The API will be similar to that used in the Qt ModelView framework. The data set that you are plotting will emit (either manually in a custom sub-class or by calling the append() function of one of the provided convenience classes) an internal signal that is connected to the data series (the graphical representation).

    This sounds simple and nice. I like the idea of having a similar API as Qt's ModelView framework. Looking forward to trying it and seeing how it performs.

    bq. What sort of data do you want to plot as a scrolling image?

    I was thinking of spectrogram-like data. Let's say you want to show a spectrogram of an audio stream scrolling while it is playing.

    Another visualization I would be interested in, is a plot that that changes entirely very frequently. Such as the instantaneous spectrum of an audio stream. But I can imagine the API, if it will be similar to the ModelView framework.

    If I didn't explained myself well, checkout the "SonicVisualiser":http://www.sonicvisualiser.org/ for the sort of plots I am interested in.

    Finally my last question is if you plan to publish your library under some Free software license?



  • Yes that is what I thought you meant but thought I should check. I will try to add in support for that type of plot but I am not sure if it will make it into version 1.

    As for the license I am planning to release it under a commercial license plus one or more FOSS licenses. I just wish I had more time to work on it but I am very busy at work at the moment.



  • Just a quick note to report a little bit of progress. I now have this charting component working under the Qt Simulator target. Next step is to get it working on a real Symbian device. Here's a "screenshot":http://gallery.theharmers.co.uk/picture.php?/165/category/5 showing a simple example running under the simulator.



  • Looking really good! Can't wait to get my hands on this.



  • hi,

    really nice plots !

    Do you use QGraphicsPathItems for the "line" plots?
    And the points symbols?

    the look and feel seems to be really well defined, yes I'd like to play with !

    great project,

    Michel



  • [quote author="Michel Pacilli" date="1307918063"]hi,
    really nice plots !
    [/quote]

    Thank you.

    [quote author="Michel Pacilli" date="1307918063"]
    Do you use QGraphicsPathItems for the "line" plots?
    And the points symbols?
    [/quote]

    Almost. I have written my own custom QGraphicsItem subclasses. In this case the lines are drawn by a ZSplinePathItem and the points are drawn by ZPointItem. Both these classes inherit from another class of mine called ZTransformedPlotItem which allows the subclasses to easily perform transformations between the natural plot coordinate system and the usual QGraphicsView parent item coordinate system. The idea being that by replacing the coordinate system in use you can change the plot type ie switch to a polar coordinate system.

    The ZSplinePathItem uses a QPainterPath internally.

    [quote author="Michel Pacilli" date="1307918063"]
    the look and feel seems to be really well defined, yes I'd like to play with !

    great project,

    Michel[/quote]

    Thank you again. I have a little more work left to do before I will make a first release but I am slowly getting there. Things left to do include:

    • Contour plots (these are almost done)
    • Bar/column charts
    • More style abstractions for easier customisation
    • Peformance optimisations
    • Lots more testing ;-)

    I'll post back here as I make progress.



  • Woohoo! I've just managed to get the basic plot example (shown above running in the simulator) to run natively on Symbian^3. This feels like a major step for me and it shows that we can now relatively easily create applications containing charts on desktop, embedded and mobile targets. :D

    The only changes I made compared to the same example built for desktop was to make the font size a little smaller to make better use of the available space and to call QWidget::showFullScreen() rather than QWidget::show() on the QGraphicsView. I'll try to factor the font size adjustments into the library. The choice between show() and showFullScreen() is down to the application writer.



  • Looks amazing can't wait to try it out :)



  • Thanks Zester. Not too long now hopefully.



  • "This question":http://developer.qt.nokia.com/forums/viewthread/6950/ was split off as a separate topic.



  • Can't wait to give it a try! Great work.
    Any idea when we shall have the chance to play with it?



  • Thx rafy. A few months I expect. I am working on the last couple of features for version 1.0 then I need to do lots of code tidy up and bug fixing ;-) As always my time is limited though.



  • Great work, Sean, i do really like your Charting Component :D



  • I now have the basics of contour plots working too. At the moment it just uses the Henry Ford colour scheme though so still work to do on making them look blingtastic ;-)



  • Hey Sean,

    Impressive work!

    Charttypes that I miss in your list are the financial stock charts like bar charts (open, high, low, close) and candlestick charts. I know that many developers are looking for something like that. I am using qwt for that purpose but it does not support these types either.

    It would be great to have these as well.

    Kind regards,
    Eric



  • Hi Eric, I have financial stock charts on my todo list but probably not for version 1.0. The good news is they should be very simple to add in.



  • Ok good. Can't wait for your first release.



  • Sean,

    Bump.

    How can I use your widget from within QML?
    Can I draw xy science plots using data from a C++ class (say a std::vector) ?
    In my app, the data may arrive any time, so how can I notify the plot widget to draw the new data?
    Is there an example ?

    Thank you for the great work. It seems what a lot of people have been waiting for!



  • How is it going on with version 1.0? Can't wait to play with it.
    Raph



  • Hey Guys,

    sorry for the delays on this. I'm in the middle of changing jobs and things are very hectic still at my existing job. I hope to get version 1.0 out very soon now.

    Victor: I am playing around with an idea on how to integrate this into QML 1. As for QML 2 I am not sure what is the best route to go down as yet so that requires some more experimentation.



  • Just wondering... will this project clash with the product portfolio of your new employer?



  • Potentially yes. Something to be resolved...



  • Thanks for the update.

    If you need a guinea pig I would enjoy helping. QML2 is fine.

    BTW, Good Luck with your new position! I know how crazy that can be.



  • Are you still working on the project?
    I hope so!



  • Anything new on this?
    I'm really keen on playing with it.



  • +1

    Best regards



  • Sean,

    This looks impressive. I've been toying with idea of adding graphing to my code and my main choice was QWT. I'd love to give this API a shot. By the way, I'm interested in plotting real-time data so the performance aspect would be important. Do you have a time-frame for when this might be available?

    Thanks

    BmanC



  • Hi Sean,

    I'm guessing you're not going to publish your component anymore?

    Just let us know to put us out of our misery, as a component like this would save me A LOT of time on a personal project I'm currently working on



  • Hi,

    I am still trying to sort out some things with my employer here. I have not forgotten about this but I have been super busy lately. Please bear with me for a little while.



  • Hi,
    where can i download the ZTPlot library? i'm quite interested to use it inside my own project

    thanks
    F.



  • [quote author="Cuke" date="1332835709"]Hi,
    where can i download the ZTPlot library? i'm quite interested to use it inside my own project

    thanks
    F.[/quote]
    At this moment, you can't yet. Sorry!



  • This is just what I'm looking for. Can I get a status update? Can ZTPlot do slide plots? Thank you.



  • Hello,

    Thank you for the post would be interested too by.

    Skylar



  • Hello,
    I'm also interested on this project. I hope you will be able to publish at some point.



  • Would love to play with this library too.



  • I am also interested in the progress of your library. Can you give us an update when it will be available?

    Best regards.





  • Ah, thanks for the hint. That thread also contains an interesting link to another library:

    "QCustomPlot":http://www.workslikeclockwork.com/index.php/components/qt-plotting-widget/


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