programs_17d.m

《Dynamical Systems with Applications using MATLAB》源代码

% Chapter 17 - Neural Networks.
% Programs_17d - The minimal chaotic neuromodule.
% Copyright Birkhauser 2004. Stephen Lynch.

% A chaotic attractor for a neural network (Figure 17.13).
clear
b1=-2;b2=3;w11=-20;w21=-6;w12=6;a=1;
N=7000;
x(1)=0;
y(1)=2;
for n=1:N
    x(n+1)=b1+w11*1/(1+exp(-a*x(n)))+w12*1/(1+exp(-a*y(n)));
    y(n+1)=b2+w21*1/(1+exp(-a*x(n)));
end 

hold on
axis([-15 5 -5 5])
plot(x(50:N),y(50:N),'.','MarkerSize',1);
fsize=15;
set(gca,'xtick',[-15:5:5],'FontSize',fsize)
set(gca,'ytick',[-5:5:5],'FontSize',fsize)
xlabel('\itx','FontSize',fsize)
ylabel('\ity','FontSize',fsize)
hold off

% End of Programs_17d.