void gaussian(const OSubLattice<T,S>& dd)
void gaussian(OLattice<T>& d, const OrderedSubset& s)
void gaussian(const OSubLattice<T,S>& dd){  OLattice<T>& d = const_cast<OSubLattice<T,S>&>(dd).field();  const S& s = dd.subset();  gaussian(d,s);}