Get the points of a fitted curve

[giusepped]

If all you want to do is to fill the area below the curve better use QwtPlotCurve::setBrush instead.

Uwe

Thank you, but I need them in order to compute the area. Is there any method in Qwt to compute the area under the curve (not just filling)?

[giusepped]

I have no idea how to get the data of the fitted curve
I use the attribute "Fitted" in setCurveAttribute.
Now, in order to compute the area I should have an array of values of the generated curve.
I see in Qwt:

canvasMap() which returns the map.
And then?

[giusepped]

I tried the following code:
(I have 12 curves called dSolar)

QwtSplineCurveFitter *c;
QwtSpline  s;
 c=(QwtSplineCurveFitter*)dSolar[11]->curveFitter();
 
 s=c->spline();
 double inter = s.value(0);
 qDebug()<<"Data size="<<dSolar[11]->dataSize()<<s.value(0)<<s.value(180);

QwtSplineCurveFitter *c;
QwtSpline  s;
 c=(QwtSplineCurveFitter*)dSolar[11]->curveFitter();
 
 s=c->spline();
 double inter = s.value(0);
 qDebug()<<"Data size="<<dSolar[11]->dataSize()<<s.value(0)<<s.value(180);

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but I get alwasy zero values...