Not enough input arguments.

i am getting error like:

>> run_Lp

xstart =

0 0 1

Not enough input arguments.

Error in l_ext (line 11)

f(2)=-x(1).*x(3)+R*x(1)-x(2);

Error in odearguments (line 90)

f0 = feval(ode,t0,y0,args{:}); % ODE15I sets args{1} to yp0.

Error in ode45 (line 106)

odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);

Error in lya (line 19)

[T,Y] = ode45(rhs_ext_fcn,[t t+stept],x,R);

Error in run_Lp (line 9)

lk= lya(n,rhs_ext_fcn,tstart,stept,tend,xstart,R);

>>

[Torsten]

run_LP has several inputs. Where do you supply them ?

Just writing "run_LP" in the command window will make MATLAB error.

[Sam Chak]

Guess you want to find the Lyapunov exponents of the Lorenz system?

[nune pratyusha]

yes, I want lyapunov exponent v/s parameters plot so, i am trying it

Answer 1

[Jan]

Do not provide parameters as appended variables in the ODE45 call:

% In lya:
[T,Y] = ode45(rhs_ext_fcn,[t t+stept],x,R);
%                                       ^  nope

Use an anonymous function to provide parameters:

% in run_Lp:
% Nope: rhs_ext_fcn = @l_ext;
R_max=10; 
R_min=1; nk=10; tstart=0; stept=0.5; tend=20; xstart=[0 0 1]
R_step=(R_max-R_min)/nk;
R=R_min;

rhs_ext_fcn = @(x, t) l_ext(x, t, R);

[nune pratyusha]

I tried your suggestion then also error is coming like

>> run_Lp

xstart =

0 0 1

Unrecognized function or variable 'R'.

Error in run_Lp>@(x,t)l_ext(x,t,R) (line 4)

rhs_ext_fcn=@(x,t) l_ext(x,t,R);R_max=10;R_min=1;nk=10;tstart=0;stept=0.5;tend=20;xstart=[0 0 1]

Error in odearguments (line 90)

f0 = feval(ode,t0,y0,args{:}); % ODE15I sets args{1} to yp0.

Error in ode45 (line 106)

odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);

Error in lya (line 19)

[T,Y] = ode45(rhs_ext_fcn,[t t+stept],xstart);

Error in run_Lp (line 9)

lk= lya(n,rhs_ext_fcn,tstart,stept,tend,xstart);

>>

[Stephen23]

@nune pratyusha: this line:

rhs_ext_fcn=@(x,t) l_ext(x,t,R);

requires R to be already defined. However in your code you define R nine lines later, which will not work.

Solution: define R before that line:

R = ..                           % <---- define R
rhs_ext_fcn=@(x,t) l_ext(x,t,R); % <---- before you refer to R here

[nune pratyusha]

if i am giving R=1:0.1:20;

it showing error like

>> run_Lp

xstart =

0 0 1

Index exceeds the number of array elements. Index must not exceed 3.

Error in l_ext (line 5)

X= [x(4) x(7) x(10);

Error in run_Lp>@(t,x)l_ext(t,x,R) (line 7)

rhs_ext_fcn=@(t,x) l_ext(t,x,R);

Error in odearguments (line 90)

f0 = feval(ode,t0,y0,args{:}); % ODE15I sets args{1} to yp0.

Error in ode15s (line 152)

odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);

Error in lya (line 19)

[T,Y] = ode15s(rhs_ext_fcn,[t t+stept],xstart);

Error in run_Lp (line 10)

lk= lya(n,rhs_ext_fcn,tstart,stept,tend,xstart);

>>

[Stephen23]

@nune pratyusha: originally you defined

R=R_min;

why are you now defining it as

R=1:0.1:20;

?

In any case, the cause of the error is clear: inside L_EXT() you are trying to access elements 4-10 of array x which only has 3 elements. Trying to access non-existent array elements throws an error. This is to be expected.

You defined XSTART to have three elements, therefore the x array inside the objective function will also have three elements.

I strongly recommend that you have only one assignment per line, and align your code consistently.

[nune pratyusha]

i changed the code but i didn't get any output

function run_Lp(n,rhs_ext_fcn,tstart,stept,tend,xstart,nk);

figure()

hold on;

n=3;

R_max=10;R_min=1;nk=10;tstart=0;stept=0.5;tend=20;xstart=[0 0 1]

R_step=(R_max-R_min)/nk;

R=1:R_step:10; R =R+R_step;

rhs_ext_fcn=@(t,x) l_ext(t,x,R);

while R<=R_max

lk= lya(n,rhs_ext_fcn,tstart,stept,tend,xstart);

R =R+R_step;

plot(R,lk);

end

[Stephen23]

@nune pratyusha: the WHILE loop never runs.

Consider your variables:

R_max =
    10
R =
    1.9000    2.8000    3.7000    4.6000    5.5000    6.4000    7.3000    8.2000    9.1000   10.0000   10.9000

which you use on this line:

while R<=R_max

The WHILE documentation states "An expression is true when its result is nonempty and contains only nonzero elements (logical or real numeric). Otherwise, the expression is false."

Question: are all of the expression elements you provide to WHILE true?

Answer: no (because 10.9 is greater than 10, so that last element will be false).

So your WHILE loop never runs.

I doubt that R should be a vector.

I strongly recommend that you have one assignment per line, and consistently align your code.