copy_site(PMatrix<T,N,C>& d, int isite, const PScalar<T1>& s1)
copy_site(PMatrix<T,N,C>& d, int isite, const PMatrix<T1,N,C>& s1)
copy_site(PMatrix<T,N,C>& d, int isite, const PScalar<T1>& s1){  for(int i=0; i < N; ++i)    for(int j=0; j < N; ++j)      copy_site(d.elem(i,j), isite, s1.elem());}