Using QwtlegendData to Display a new column in the legend

[Uwe]

Well, in general you can overload QwtAbstractLegend::updateLegend() to do whatever you want with these additional attributes. You could even implement your own style of legend, like it is done in the stockchart example.
But why not setting up a signal/slot connection between picker and legend - sounds more logical to me than passing those attributes as legend data ?

Uwe