close all
%create kernel matrix
slen=100;
M=dft(slen);
%plot kernel matrix
if 1==1

  subplot(121)
  surf(real(M));view(2);shading('interp');colormap('gray'); xlabel('real part')
  subplot(122)
  surf(imag(M));view(2);shading('interp');colormap('gray'); xlabel('imag part')
end
