code: private void setEAxis() {
  		Rotation e = rotations.get(0);
  		Rotation h = rotations.get(principalAxisIndex);
  		e.setAxisAngle(new AxisAngle4d(h.getAxisAngle()));
  		e.getAxisAngle().angle = 0.0;
  		e.setFold(h.getFold());
  	}
docs: Add E operation to the highest order rotation axis. By definition
  E belongs to the highest order axis.