Double_t distance;
distance =
TMath::Sqrt(fabs(((wire1-vpf).Mag2()*(wire2-wire1).Mag2()-pow((wire1-vpf).Dot(w$
// check vpf inside tube
if(distance>0.5) {
  cout << "vpf outside the firing tube" << endl;
  FitterException exc("distance vpf-wire > 0.5", __LINE__,__FILE__);
  throw exc;
}