LeastSquaresFitting::InitialGuessForLeastSquaresFitting LeastSquaresFitting::findInitialGuess(const Handle_TColgp_HArray1OfPnt& points)
{
	//Compute center of gravity for point set
	double cx=0.0;
	double cy=0.0;

	for(Standard_Integer i=points->Lower();i<=points->Upper();i++)
	{
		cx += points->Value(i).X();
		cy += points->Value(i).Y();
	}

	cx /= points->Length();
	cy /= points->Length();

	gp_Pnt centerPoint(cx,cy,0.0);

	//Compute average radius
	double averageRadius = 0.0;
	for(Standard_Integer i=points->Lower();i<=points->Upper();i++)
	{
		averageRadius += centerPoint.Distance(points->Value(i));
	}
	averageRadius /= points->Length();

	return InitialGuessForLeastSquaresFitting(centerPoint,averageRadius);
}
PyObject* BSplineCurvePy::interpolate(PyObject *args)
{
    PyObject* obj;
    double tol3d = Precision::Approximation();
    PyObject* periodic = Py_False;
    PyObject* t1=0; PyObject* t2=0;
    if (!PyArg_ParseTuple(args, "O|O!dO!O!",&obj, &PyBool_Type, &periodic, &tol3d,
                                            &Base::VectorPy::Type, &t1, &Base::VectorPy::Type, &t2))
        return 0;
    try {
        Py::Sequence list(obj);
        Handle_TColgp_HArray1OfPnt interpolationPoints = new TColgp_HArray1OfPnt(1, list.size());
        Standard_Integer index = 1;
        for (Py::Sequence::iterator it = list.begin(); it != list.end(); ++it) {
            Py::Vector v(*it);
            Base::Vector3d pnt = v.toVector();
            interpolationPoints->SetValue(index++, gp_Pnt(pnt.x,pnt.y,pnt.z));
        }

        if (interpolationPoints->Length() < 2) {
            Standard_Failure::Raise("not enough points given");
        }

        GeomAPI_Interpolate aBSplineInterpolation(interpolationPoints,
            PyObject_IsTrue(periodic) ? Standard_True : Standard_False, tol3d);
        if (t1 && t2) {
            Base::Vector3d v1 = Py::Vector(t1,false).toVector();
            Base::Vector3d v2 = Py::Vector(t2,false).toVector();
            gp_Vec initTangent(v1.x,v1.y,v1.z), finalTangent(v2.x,v2.y,v2.z);
            aBSplineInterpolation.Load(initTangent, finalTangent);
        }
        aBSplineInterpolation.Perform();
        if (aBSplineInterpolation.IsDone()) {
            Handle_Geom_BSplineCurve aBSplineCurve(aBSplineInterpolation.Curve());
            this->getGeomBSplineCurvePtr()->setHandle(aBSplineCurve);
            Py_Return;
        }
        else {
            Standard_Failure::Raise("failed to interpolate points");
            return 0; // goes to the catch block
        }
    }
    catch (Standard_Failure) {
        Handle_Standard_Failure e = Standard_Failure::Caught();
        std::string err = e->GetMessageString();
        if (err.empty()) err = e->DynamicType()->Name();
        PyErr_SetString(PartExceptionOCCError, err.c_str());
        return 0;
    }
}
PyObject* BSplineCurvePy::interpolate(PyObject *args, PyObject *kwds)
{
    PyObject* obj;
    PyObject* par = 0;
    double tol3d = Precision::Approximation();
    PyObject* periodic = Py_False;
    PyObject* t1 = 0; PyObject* t2 = 0;
    PyObject* ts = 0; PyObject* fl = 0;
    PyObject* scale = Py_True;

    static char* kwds_interp[] = {"Points", "PeriodicFlag", "Tolerance", "InitialTangent", "FinalTangent",
                                  "Tangents", "TangentFlags", "Parameters", "Scale", NULL};

    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|O!dO!O!OOOO!",kwds_interp,
                                     &obj, &PyBool_Type, &periodic, &tol3d,
                                     &Base::VectorPy::Type, &t1,
                                     &Base::VectorPy::Type, &t2,
                                     &ts, &fl, &par, &PyBool_Type, &scale))
        return 0;

    try {
        Py::Sequence list(obj);
        Handle_TColgp_HArray1OfPnt interpolationPoints = new TColgp_HArray1OfPnt(1, list.size());
        Standard_Integer index = 1;
        for (Py::Sequence::iterator it = list.begin(); it != list.end(); ++it) {
            Py::Vector v(*it);
            Base::Vector3d pnt = v.toVector();
            interpolationPoints->SetValue(index++, gp_Pnt(pnt.x,pnt.y,pnt.z));
        }

        if (interpolationPoints->Length() < 2) {
            Standard_Failure::Raise("not enough points given");
        }

        Handle_TColStd_HArray1OfReal parameters;
        if (par) {
            Py::Sequence plist(par);
            parameters = new TColStd_HArray1OfReal(1, plist.size());
            Standard_Integer pindex = 1;
            for (Py::Sequence::iterator it = plist.begin(); it != plist.end(); ++it) {
                Py::Float f(*it);
                parameters->SetValue(pindex++, static_cast<double>(f));
            }
        }

        std::unique_ptr<GeomAPI_Interpolate> aBSplineInterpolation;
        if (parameters.IsNull()) {
            aBSplineInterpolation.reset(new GeomAPI_Interpolate(interpolationPoints,
                PyObject_IsTrue(periodic) ? Standard_True : Standard_False, tol3d));
        }
        else {
            aBSplineInterpolation.reset(new GeomAPI_Interpolate(interpolationPoints, parameters,
                PyObject_IsTrue(periodic) ? Standard_True : Standard_False, tol3d));
        }

        if (t1 && t2) {
            Base::Vector3d v1 = Py::Vector(t1,false).toVector();
            Base::Vector3d v2 = Py::Vector(t2,false).toVector();
            gp_Vec initTangent(v1.x,v1.y,v1.z), finalTangent(v2.x,v2.y,v2.z);
            aBSplineInterpolation->Load(initTangent, finalTangent, PyObject_IsTrue(scale)
                                        ? Standard_True : Standard_False);
        }
        else if (ts && fl) {
            Py::Sequence tlist(ts);
            TColgp_Array1OfVec tangents(1, tlist.size());
            Standard_Integer index = 1;
            for (Py::Sequence::iterator it = tlist.begin(); it != tlist.end(); ++it) {
                Py::Vector v(*it);
                Base::Vector3d vec = v.toVector();
                tangents.SetValue(index++, gp_Vec(vec.x,vec.y,vec.z));
            }

            Py::Sequence flist(fl);
            Handle_TColStd_HArray1OfBoolean tangentFlags = new TColStd_HArray1OfBoolean(1, flist.size());
            Standard_Integer findex = 1;
            for (Py::Sequence::iterator it = flist.begin(); it != flist.end(); ++it) {
                Py::Boolean flag(*it);
                tangentFlags->SetValue(findex++, static_cast<bool>(flag) ? Standard_True : Standard_False);
            }

            aBSplineInterpolation->Load(tangents, tangentFlags, PyObject_IsTrue(scale)
                                        ? Standard_True : Standard_False);
        }

        aBSplineInterpolation->Perform();
        if (aBSplineInterpolation->IsDone()) {
            Handle_Geom_BSplineCurve aBSplineCurve(aBSplineInterpolation->Curve());
            this->getGeomBSplineCurvePtr()->setHandle(aBSplineCurve);
            Py_Return;
        }
        else {
            Standard_Failure::Raise("failed to interpolate points");
            return 0; // goes to the catch block
        }
    }
    catch (Standard_Failure) {
        Handle_Standard_Failure e = Standard_Failure::Caught();
        std::string err = e->GetMessageString();
        if (err.empty()) err = e->DynamicType()->Name();
        PyErr_SetString(PartExceptionOCCError, err.c_str());
        return 0;
    }
}