OLattice<T>  r1, r2;
OLattice<T>& d = const_cast<OSubLattice<T,S>&>(dd).field(); const S& s = dd.subset();
void gaussian(OLattice<T>& d, const OrderedSubset& s){  OLattice<T>  r1, r2;  random(r1,s);  random(r2,s);  const int istart = s.start() >> INNER_LOG;  const int iend   = s.end()   >> INNER_LOG;  for(int i=istart; i <= iend; ++i)     fill_gaussian(d.elem(i), r1.elem(i), r2.elem(i));}