Use the Plot2d Component to create a basic plot to show as an overlay item in the view.
double curvex[] = { 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0 };
double curve1y[] = { 0.0, 1.2, 3.3, 4.0, 3.0, 2.9, 2.8, 2.7, 2.7, 2.7 };
double curve2y[] = { 0.0, 1.5, 4.3, 5.0, 4.0, 3.8, 3.5, 3.0, 2.8, 2.7 };
std::vector<double> xValues(curvex, curvex + 10);
std::vector<double> y1Values(curve1y, curve1y + 10);
std::vector<double> y2Values(curve2y, curve2y + 10);
plot->
addCurve(
"First curve", xValues, y1Values);
plot->
addCurve(
"Second curve", xValues, y2Values);