error in plotting lyapunov exponent from time series

Is there any command to plot maximal lyapunov exponent from time series for which i tried my own codes. but still i m in a stage where i get the error:

r =

0

??? Subscript indices must either be real positive integers or logicals.

Error in ==> mlcmainbifr at 10 lyap1=lyap([t,x(:,1)]); pls help me in giving any idea and best suggestions.

kinds regards matlab codes:

clc

global r

for r=0.0:0.1:30 r

lyap(1)=.01;

[t,x]=ode45('loreeneq',0:1:500,[.01,.01,.01]);

lyap1=lyap([t,x(:,1)]);

plot(r,lyap1,'r');

drawnow

end

xlabel ('r');ylabel('lyap') ---------------------------------------------------------------------- function dxdt=loreeneq(t,x)

global r

dxdt1=10*(x(2)-x(1));

dxdt2=(r*x(1))-x(2)-(x(1)*x(3));

dxdt3=(x(1)*x(2))-(2.67*x(3));

dxdt=[dxdt1;dxdt2;dxdt3];

Answer 1

[Andrew Newell]

Is lyap supposed to be a variable or the function in the Control Toolbox? If the former, you can't index it with t and x because they are real variables, not integers. I can't suggest a fix because I don't know what you are trying to do in enough detail.

You might be able to use Calculation Lyapunov Exponents for ODE from the File Exchange.