howto get value at Tracker Point

[pospiech]

In my zoomer class I also set the tracker:

virtual QwtText trackerText( const QwtDoublePoint& p ) const 
    {
        QwtText t( QwtPlotPicker::trackerText( p ));
 
	QColor c(Qt::white);
        c.setAlpha(180);
        t.setBackgroundBrush( QBrush(c) );
 
        return t;
    }

virtual QwtText trackerText( const QwtDoublePoint& p ) const 
    {
        QwtText t( QwtPlotPicker::trackerText( p ));

	QColor c(Qt::white);
        c.setAlpha(180);
        t.setBackgroundBrush( QBrush(c) );

        return t;
    }

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This returns the axis coordinates.

I would also like to display the vlaue at the current point. However I do not know how to access this value at this point. The qwtPlot istself is known as the pointer 'plot' within the Zoomer class.