void FairModule::SetDefaultMatrixName(TGeoMatrix* matrix)
{
  // Copied from root TGeoMatrix::SetDefaultName() and modified (memory leak)
  // If no name was supplied in the ctor, the type of transformation is checked.
  // A letter will be prepended to the name :
  //   t - translation
  //   r - rotation
  //   s - scale
  //   c - combi (translation + rotation)
  //   g - general (tr+rot+scale)
  // The index of the transformation in gGeoManager list of transformations will
  // be appended.
  if (!gGeoManager) return;
  if (strlen(matrix->GetName())) return;
  char type = 'n';
  if (matrix->IsTranslation()) type = 't'; 
  if (matrix->IsRotation()) type = 'r';
  if (matrix->IsScale()) type = 's';
  if (matrix->IsCombi()) type = 'c';
  if (matrix->IsGeneral()) type = 'g';
  TObjArray *matrices = gGeoManager->GetListOfMatrices();
  Int_t index = 0;
  if (matrices) index =matrices->GetEntriesFast() - 1;
  matrix->SetName(Form("%c%i", type, index));
}