Data plot for different values

I want plot theta as a function of z at t = time(nt) for all xi values but receive: Error using plot: Data cannot have more than 2 dimensions om line 140.

Answer 1

[Torsten]

%store your outputs for each xi
thetaxivalues(ixi,:,:) = theta(:,:);
vxivalues(ixi,:,:) = v(:,:);

What is ixi ? I guess, it's a single scalar, namely ixi = nxi from the last loop where ixi appears:

for ixi = 1:length(xivalues)
    xi = xivalues(ixi);
end

So you don't store outputs for each xi.

[University Glasgow]

I actually wants the xi to take values from xivalues = linspace(-0.3, -0.1, nxi).

[Torsten]

But your vector "theta" does not depend on xi.

So it makes no sense to set

thetaxivalues(1:nxi,:,:) = theta(:,:);
vxivalues(1:nxi,:,:) = v(:,:);

because every vector thetaxivalues and vxivalues will contain the same values for 1 <= ixi <= nxi.

[University Glasgow]

You are right but what do you suggest then?

[Torsten]

Your simulations must contain xi as a parameter and you must vary this parameter to get theta(xi,:,:) and v(xi,:,:).

[University Glasgow]

Please, could you help me out.

[Torsten]

How could I ?

I don't know anything about your model, and at the moment, I don't see a variable xi within the equations in lcode1 that could be varied.

[University Glasgow]

If you cehck the discretised equations, I have xi in the v equation.

Please check, you will see: (xi/(2*h))*(theta(N-1)-theta(N-3));

[Torsten]

Then call the solver in a loop over the elements of xi and write the results in a 3d v and theta array.

But that's really standard and I won't do that for you.