function Xopout=xop(dz,dy,n,mm)
%        Xopout=xop(dz,dy,n,mm)
%  maps (dz,dy) in RxR^{mm} ---> R^{n,n}
%         vectors   to  matrix space n by n

global indsE X 
Xopout=usMatE(dy,n,mm);
Xopout(1:n+1:end)=diag(Xopout)+dz;
Xopout=Xopout*X;
%Xopout=( dz*speye(n)+usMatE(dy,n,mm) )*X;  % old way
