function [is, ie] = zpzh_idxs(N)
md2 = mod(N,2);
if md2 == 1
  is =  (N + md2)/2:N;
  ie = 1:(N + md2 - 1)/2;
else
  is =  N/2+1:N;
  ie = [1:N /2];
end

end