%kawakami超混沌序列
L=6000;%相關運算的長度
x=zeros(1,L);
x(1)=0.400001;
y(1)=0.010007;
for i=1 : L
    x(i+1) = -0.125 * x(i) + y(i);
    y(i+1) = x(i) * x(i) - 1.5;
end
crx=xcorr(x,'unbiased');
plot(crx);
axis([1000 2*L-1000 min(crx) max(crx)]);
figure;

z=zeros(1,L);
z(1)=0.400002;
w(1)=0.010007;
for i=1 : L
    z(i+1) = -0.125 * z(i) + w(i);
    w(i+1) = z(i) * z(i) - 1.5;
end
crz=xcorr(z,'unbiased');
plot(crz);
axis([1000 2*L-1000 min(crz) max(crz)]);
figure;

crxz=xcorr(x,z,'unbiased');
plot(crxz);
axis([1000 2*L-1000 min(crxz) max(crxz)]);