Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
NCTM or The Math Forum.


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!!!



