void MinFCN(int& /*npar*/, double* /*gin*/, double& f,
			   double* par, int /*iflag*/)
{

  double x[10] = {0, 1, 1, 2, 3, 5, 6, 8, 8.5, 9};
  double y[10] = {-0.110079, 1.91072, 1.89933, 3.95169, 6.12023,
		  10.1611, 12.5725, 17.4555, 15.9894, 17.0093};

  for (int i = 0; i < 10; ++i) {
    double dy = par[0] + par[1] * x[i] - y[i];
    f += dy * dy;
  }
}

void doMinuit()
{
  
  TMinuit* minu = new TMinuit(2);
  minu->SetFCN(MinFCN);  
  minu->SetPrintLevel(-1);
  minu->DefineParameter(0, "Offset", 0, 0.1, -0.5, 0.5);
  minu->DefineParameter(1, "Slope",  1.6, 0.2, 1.5, 2.5);
  minu->Migrad();
}