function ubar = my_r2hc(u)
%
% FFTWs R2HC: Re & IM components of firat 0:n/2 complex output terms 
%            r0,r1,r2,...,r(n/2-1),r(n/2),i(n/2-1),...,i2,i1
%
N = length(u);  % we assume N is even
uhat = fft(u);
ubar = [real(uhat(1));     real(uhat(2:N/2)); ...
        real(uhat(N/2+1)); imag(uhat(N/2:-1:2))]; 

