// Action_CheckStructure::SeparateInit()
int Action_CheckStructure::SeparateInit(bool imageOn, std::string const& mask1,
                                        std::string const& mask2, std::string const& fname,
                                        double cutIn, double offsetIn, bool silentIn,
                                        DataFileList& DFL)
{
  image_.InitImaging( imageOn );
  bondoffset_ = offsetIn;
  nonbondcut2_ = cutIn * cutIn; // Save cutoff squared.
  silent_ = silentIn;
  if (!silent_)
    outfile_ = DFL.AddCpptrajFile(fname, "Structure check", DataFileList::TEXT, true);
  Mask1_.SetMaskString( mask1 );
  if (!mask2.empty())
    Mask2_.SetMaskString( mask2 );
  return 0;
}