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Topic: Incomplete diagram!
Replies: 2   Last Post: Jul 12, 2013 5:38 PM

 Messages: [ Previous | Next ]
 Sanaa Posts: 171 Registered: 3/20/12
Re: Incomplete diagram!
Posted: Jul 12, 2013 5:38 PM

"someone" wrote in message <krp8jm\$lm\$1@newscl01ah.mathworks.com>...
> "Sanaa" wrote in message <krot0k\$q4g\$1@newscl01ah.mathworks.com>...
> > Hi,
> > I have a problem that I wish to plot what is called a bifurcation diagram.
> > The map under study is given by
> > x_((n+1)r)= 1 - ru *x^2_(nr),
> > where r is a positive constant may take 0.1,0.2,...
> > ru is a positive parameter, and the time t runs from nr to (n+1)r, n=0,1,2,...
> >
> > I have the matlab code
> > %%%%%%%%%
> >
> > % define the vector of values that r takes
> > r_vec = [0.2];
> > % define the vector of colors, to plot the dat aof reach value of r in
> > % different color
> > color_vec = ['b'];
> >
> > for rho = 0: 0.005: 2
> >
> >
> > % do a loop of values of r
> > for j = 1 : size(r_vec,2)
> > % define delay
> > r = r_vec(j);
> > % define coefficient rho
> > %rho = 0.5;
> > % define the number of deiscrete times in interval [k*r, (k+1)*r]
> > n = 10;
> > % define the nimber of iterations k = 1,.....,Nit
> > Nit = 1000;
> > % define the initial vector which is a vector of size n
> > x0 = 0.3*ones(1,n);
> > % define vectors x_next and x_previous
> > x_next = zeros(1,n);
> > x_previous = zeros(1,n);
> > time = zeros(1,n);
> >
> > % initialize x_previous
> > x_previous = x0;
> > x_next = x_previous;
> > time = linspace(0,r,n);
> >
> > % set the figure details
> > figure(1)
> > xlabel('t')
> > ylabel('x')
> > %plot(time,x_next,'*')
> > hold on
> > for i = 1:Nit
> >
> > x_next = 1 - rho*x_previous.^2;
> > x_previous = x_next;
> > time = linspace(i*r,(i+1)*r,n);
> >
> > end
> > end
> >
> >
> > plot(rho,x_next(1),'.', 'Color', char(color_vec(j)),'linewidth',10)
> >
> > end
> >
> > hold off
> > % save the figure
> > % print -depsc map.eps
> > %%%%
> > The code works but I am wondering why I don't get a complete picture of the diagram, it seems that it is divided into 2 parts!!!!
> > Any help please.

>
> I don't have MATLAB installed on this computer, but from the above my guess is to move the statements:
>
> % set the figure details
> figure(1)
> xlabel('t')
> ylabel('x')
> %plot(time,x_next,'*')
> hold on
>
> before your outer loop and see what happens. I suspect the statement "figure(1) is executed twice and that is why your diagram is divided into 2 parts (as you state). But this is just a guess!

Thanks a lot for your reply. Howerver, I didn't get any figure al all!!!

Date Subject Author
7/12/13 Sanaa
7/12/13 Curious
7/12/13 Sanaa