%Usage   A=cz(n,val);   %returns a Calderon-Zygmund matrix
%                        n = size of matrix
%                        a = value on diagonal
%
% e.g. A=cx(64,2);  %val=2 is put on the main digaonal

function A=CZ(n,a);
 if nargin<1,help cz, return;end
A=a*ones(n,n);
for i=1:n
   for j=i+1:n
      A(i,j)=1/(j-i); A(j,i)=1/(j-i);
   end
end
