%create kernel matrix
slen=100;
M=dft(slen);

%example one impulse response delayed by one
if 1==1
  figure;
  x=zeros(1,slen);
  x(1)=1;
  subplot(311)
  stem(x); xlabel('signal')
  subplot(312)
  stem(abs(x*M)); xlabel('magnitude');
  subplot(313) 
  stem(angle(x*M)); xlabel('phase');
  title('impulse response')
end
