Draw a single point into a qwt plot

[Qwt_beginner]

How can i draw a single point into a Qwt-Plot?

I tried:
Whats wrong?


QwtPlotCurve *cCos = new QwtPlotCurve("y = cos(x)");
cCos->setRenderHint(QwtPlotItem::RenderAntialiased);
cCos->setLegendAttribute(QwtPlotCurve::LegendShowLine , true);
cCos->setPen(QPen(Qt::green));
QVector<double> xWerte,yWerte;
xWerte[0]=1;
yWerte[0]=0;
QwtSeriesData<QPointF> point;
point=QwtPointArrayData(xWerte,yWerte);
cCos->setData(point);
cCos->attach(ui->qwtPlot);
}

[pkj]

Set a marker for the curve. A line goes to nowhere if it is a point. How can you see it. A point has no size, does it.
use

QwtPlotCurve::setSymbol(new QwtSymbol(QwtSymbol::Style, QBrush, Qpen, Qsize))

QwtPlotCurve::setSymbol(new QwtSymbol(QwtSymbol::Style, QBrush, Qpen, Qsize))

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Hope that helps,
Cheers.

[Spitfire]

Even simpler (and more appropriate) would be to use a marker than a curve.

QwtPlotMarker* m = new QwtPlotMarker();
m->setSymbol( QwtSymbol( QwtSymbol::Diamond, Qt::red, Qt::NoPen, QSize( 10, 10 ) ) );
m->setValue( QPointF( 1.5, 2.2 ) );
m->attach( plot );

QwtPlotMarker* m = new QwtPlotMarker();
m->setSymbol( QwtSymbol( QwtSymbol::Diamond, Qt::red, Qt::NoPen, QSize( 10, 10 ) ) );
m->setValue( QPointF( 1.5, 2.2 ) );
m->attach( plot );

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