Altering Matlab Code for a Logistic Map Cobweb Plot

[Dustinsfl]

I found some Matlab code that works. However, I am not sure how to alter it for my needs.

How can I make the code work for this:$N_{t+1} = \frac{(1+r)N_t}{1+rN_t}$What needs to be changed?

%%% MAKES A COBWEB PLOT FOR A LOGISTIC MAP

% compute trajectory
a=3.0;          % parameter
x0=0.2;         % Initial condition 
N=40;           % Number of iterations
x(1) = x0;    
for ic=1:N
 x(ic+1) = a*x(ic)*(1-x(ic)); 
end

% plot the map function and the line y=x
clf;
t = 0:0.01:1;
plot(t,a*(t.*(1-t))); hold on;
 axis('square'); axis([0 1 0 1]);
 set(gca,'XTick',(0:0.1:1),'YTick',(0:0.1:1))
 grid on;

 fplot('1*y',[0 1],'r');

%%%%%% STEP 3: PLOT COBWEB
 line([x(1) x(1)],[0 x(2)],'Color','g') 
  plot(x(1), x(1),'ko');
 for ic=1:N-1
  line([x(ic) x(ic+1)],[x(ic+1) x(ic+1)],'Color','g')  
  line([x(ic+1) x(ic+1)],[x(ic+1) x(ic+2)],'Color','g')
  plot(x(ic+1), x(ic+1),'ko');
 end
 line([x(N) x(N+1)],[x(N+1) x(N+1)],'Color','g')
 
  %%%%%% STEP 4: SIGN THE PLOT
 at=text(0.1,0.82,['a=',num2str(a)]); set(at,'FontSize',12);

 

[jedishrfu]

One might be able to run this on the MATLAB Online service:

https://www.mathworks.com/products/matlab-online.html

or use the Freemat open source program.

http://freemat.sourceforge.net/download.html

Freemat supports the core MATLAB functions but maybe different from the actual MATLAB in execution. I've used it in the past and it worked well for small one off projects.

 

[Wrichik Basu]

One might be able to run this on the MATLAB Online service

MATLAB online is not free. You have to have a valid license to be able to use that. For instance, my student license entitles me to download MATLAB for offline use forever even if I do not renew (I won't get the updated version, only the one that was latest when the license expired). MATLAB Android app is, however, free to use, but the speed depends on your internet connectivity as the interpreter is on the server.