Date: Jul 12, 2013 11:50 AM
Author: Curious
Subject: Re: Incomplete diagram!
"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!