A Lorenz's system of ODEs doesn't get executed in Matlab

[MathematicalPhysicist]

I use the following script and function in MatLab, but get three errors.
I shall first write down the code and after that the errors that I get.

function yprime = lorenz_de(t,y)
%LORENZ_DE    Lorenz equations.
%   yprime  = lorenz_de(t,y).

yprime = [10*(y(2)-y(1))
          28*y(1)-y(2)-y(1)*y(3)
          y(1)*y(2)-8*y(3)/3];

%LORENZ_RUN     ODE solving example: Lorenz.

tspan = [0 50];                       % Solve for 0 <= t <= 50.
yzero = [0;1;0];                      % Initial conditions.
[t,y] = ode45(@lorenz_de,tspan,yzero);
plot(y(:,1),y(:,3))                   % (y_1,y_3) phase plane.
xlabel('y_1','FontSize',14)
ylabel('y_3 ','FontSize',14,'Rotation',0,'HorizontalAlignment','right')
title('Lorenz equations','FontSize',16,'FontWeight','normal')

Here are the errors:

Error using odearguments (line 93)
LORENZ_DE must return a column vector.

Error in ode45 (line 115)
  odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);

Error in lorenz_run (line 5)
[t,y] = ode45(@lorenz_de,tspan,yzero);

How to fix these errors?
Thanks!

 

[Orodruin]

Works perfectly fine for me:

 

[MathematicalPhysicist]

@Orodruin thanks for replying.

It seems something is wrong with my software, can you give a look at the errors I listed in my OP?
BTW which version of MatLab are you using?

I am using 2018b, and now I am downloading update 2.

 

[Orodruin]

I have a rather old version of Matlab, 2014b if I recall correctly ...

The errors suggest that your lorenz_de function does not return a column vector, but it does. The only thing I can think about is if your main file and lorenz_de are located in different folders and you have an old copy of lorenz_de lying around in the same folder as the main file.

 

[Wrichik Basu]

@MathematicalPhysicist Your code works fine in my 2019b.

One thing that you can try is to convert the function into an inner function in the script. This way, the script will only refer to the function within the script and you can avoid the the duplicate files issue stated by @Orodruin in #4.

Another option is to completely convert the script into a function. Let the inner (nested) function remain as it is. This way, there will be no collision with workspace variables, if any.

 

[MathematicalPhysicist]

It works!

Sing Halleluja!
It seems I should have saved the two files in the directory of MatLab and then make the directory into the add to path.
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