Results 1 to 2 of 2

Thread: QwtRasterData : value(x, y) : How to have always same x and y value called

  1. #1
    Join Date
    Jun 2011
    Posts
    11
    Thanks
    4
    Qt products
    Qt4
    Platforms
    MacOS X Unix/X11 Windows

    Default Re: QwtRasterData : value(x, y) : How to have always same x and y value called

    Hello,

    We have developped a WaterFall widget with the Qwt.
    We are showing it in a range of 20 second but we can also show 180 second.

    The problem is when we are showing 180s it is "blinking". This is because value is called but x and y value are different than the second before.

    It is hard to explain. But how can we be sure the value is called with the same x and y value ?

    I have a QList for each second of value depending on the x value.

    So how can i be sure that value is always called with same x value ?

    Thanks


    Added after 5 minutes:


    I used a QList<QList<double> > mDataDouble

    I add information in this Qlist every 100ms.

    Every 100 ms I do something like this :
    refreshNotPossible = true;

    // Ajout des nouvelles donnees en tete de matrice
    mDataDouble.push_front(pData);

    // Suppression des donnees trop anciennes
    if (mFrequency != 0)
    {
    double dataDoubleSize = mDataDouble.size();
    double maxDataDoubleSize = (mYMax + 1) * (1 / mFrequency);
    // On garde les donnees jusqu'au max + 1 pour eviter l'apparition d'un offset en bas du waterfall
    while (mDataDouble.size() >= 180*1000)
    {
    mDataDouble.pop_back();
    }
    }

    refreshNotPossible = false;
    And when we are in the value function, depending on the y value we are retrieving the good QList in the QList<QList> and then retreiving the good value in this QList<> using X value.

    Of course X and Y value are cast into the good interger to get the value into the QList
    Last edited by lionel.s; 9th October 2015 at 08:51.

  2. #2
    Join Date
    Feb 2006
    Location
    Munich, Germany
    Posts
    3,241
    Thanked 860 Times in 809 Posts
    Qt products
    Qt3 Qt4 Qt/Embedded
    Platforms
    MacOS X Unix/X11 Windows

    Default Re: QwtRasterData : value(x, y) : How to have always same x and y value called

    To be honest I didn't get what you are asking for ?

    Uwe

Similar Threads

  1. Replies: 0
    Last Post: 8th July 2015, 11:41
  2. Replies: 0
    Last Post: 24th September 2014, 01:53
  3. QwtPlotSpectrogram and QwtRasterData
    By jesse_mark in forum Qwt
    Replies: 10
    Last Post: 5th February 2013, 14:59
  4. QwtRasterData and values
    By DKL1972 in forum Qwt
    Replies: 12
    Last Post: 10th March 2010, 09:53
  5. Convert QwtRasterData to QwtSeriesData
    By bigjoeystud in forum Qwt
    Replies: 3
    Last Post: 25th August 2009, 15:06

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Digia, Qt and their respective logos are trademarks of Digia Plc in Finland and/or other countries worldwide.