function E=deflateEigen(E, param)
totalenergy=sum(abs(E.val));
currentenergy=0;
rank=0;
for i=1:size(E.vct,2)
if currentenergy>(totalenergy*param)
break;
end
rank=rank+1;
currentenergy=currentenergy+E.val(i);
E.val=E.val(1:rank);
E.vct=E.vct(:,1:rank);