Clip existing ContourLines of QwtPlotSpectrogram

[Uwe]

This is a bug in Qwt, but you can work around it easily:

virtual ContourLines YourRasterData::contourLines(
        const QwtDoubleRect &rect,
        const QSize &raster, const QList<double> &levels,
        int flags) const
{
    QwtDoubleRect area = rect;
    if ( boundingRect().isValid() )
        area &= boundingRect();
 
    return QwtRasterData::contourLines(area, raster, levels flags);
}

virtual ContourLines YourRasterData::contourLines(
        const QwtDoubleRect &rect,
        const QSize &raster, const QList<double> &levels,
        int flags) const
{
    QwtDoubleRect area = rect;
    if ( boundingRect().isValid() )
        area &= boundingRect();

    return QwtRasterData::contourLines(area, raster, levels flags);
}

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Or you can use the code from SVN ( 5.2 branch ).

Uwe

[Keir]

Superb! Thank you.

[jwieland]

Hi,

I am also trying to use contour in my program and confused about the qwt contour program. Do I need to implement some contour algorithm to fill my data with points of (x, y, v) or those points have been figured out by the qwt library? I mean, I have a set of (x, y, v) points but the number of those points is just a few and cannot certainly fill up all the display. And if I am to enter the data, where in the Qwt structure should I enter them?

Any help is greatly appreciated.