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Thread: Weird QwtPlotCurve Behaviour

  1. #1
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    Default Weird QwtPlotCurve Behaviour

    Hello readers,

    I'm plotting a frequency response on a QwtPlot setting the data by calling void QwtPlotCurve::setSamples(const QVector< double > & xData, const QVector< double > & yData). I'm just wondering why Qwt always draw a line from the minimum y-value to the first point in my dataset (see attached picture). I printed my QVectors on the console and can definitely confirm that the first point in my dataset is right.

    I'm coding on a Windows 7 64-Bit machine with Qt 4.8.3 and Qwt 6.1.0.

    Cheers,
    Yann
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  2. #2
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    Default Re: Weird QwtPlotCurve Behaviour

    I'm just wondering why Qwt always draw a line from the minimum y-value to the first point in my dataset (see attached picture).
    I does not.

    I printed my QVectors on the console and can definitely confirm that the first point in my dataset is right.
    Nevertheless I expect to find the reason in your dataset.

    Uwe

  3. The following user says thank you to Uwe for this useful post:

    yannwilfried (18th July 2013)

  4. #3
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    Default Re: Weird QwtPlotCurve Behaviour

    Thanks Uwe for your reply. It was indeed my bad. One has to be careful when playing around with pointers to the data stored in the QVector.

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