QCustomPlot Discussion and Comments

Gradient under the line graphReturn to overview

Dear All, I've been trying to apply a gradient to fill the space under the curve.

QLinearGradient linearGrad(QPointF(0, 0), QPointF(0, 120));
    QColor w(Qt::transparent);
    w.setAlphaF(.5);
    QColor g(Qt::red);
    g.setAlphaF(.5);
    QColor b(Qt::black);
    b.setAlphaF(.5);
    linearGrad.setColorAt(0, w);
    linearGrad.setColorAt(0.5, g);
    linearGrad.setColorAt(1, b);
...
   ui->plot->addGraph(); // yellow line: set point
   ui->plot->graph(LIVE_TEMPERATURE_GRAPH)->setBrush(linearGrad);

But is wrong because of fixed points. My problem is that I don't understand how to set the 2 points in lineadGrad. How to set the space from the x axis to each point of the curve ?
Does anybody solved this scenario ?
Thanks

QLinearGradient linearGrad(QPointF(0, 0), QPointF(0, 1));
linearGrad.setCoordinateMode(QLinearGradient::ObjectMode);
linearGrad.setColorAt(0, w);
linearGrad.setColorAt(0.5, g);
linearGrad.setColorAt(1, b);