MATLAB: Index exceeds matrix dimensions.

indexmatrix dimension

Dear All,
Can someone enlighten me by explaining why I'm getting following error message in code below?
Index exceeds matrix dimensions. Error in verysimple3 (line 14) [Tp]=ode45(@(l,Tp) myODE(l,Tp,Aap,Acp),Pool(k:k+1),y0);
If I add the parameters Aap,Acp as input parameters of my anonymous function then I get: Not enough input arguments. Error in verysimple3>@(l,Tp,Aap,Acp)myODE(l,Tp,Aap,Acp)
Sorry for this question with a probably very obvious answer! Originally I didn't want to include Aap and Acp as input parameters for myODE function as these are fixed for each interval (see loop) but I'm not sure to have another option in this case…
a =2;
b =1;
Pool = [0,a,b];
y0=30;
for k=1:numel(Pool)
    switch k
        case rem(k,2)==1
            Aap=a; Acp=Aap;
        otherwise
            Aap=2*b; Acp=0; 
    end
 
[l,Tp]=ode45(@(l,Tp) myODE(l,Tp,Aap,Acp),Pool(k:k+1),y0);
y0=y(end,1);
end
plot(l,Tp(:,:));
function dTpdl=myODE(l,Tp,Aap,Acp)
dTpdl=(140-Tp)*Acp+(100-Tp)*Aap-Aap/(Tp+273);                                                                                           
end

Best Answer

See my answer to your former question: https://www.mathworks.com/matlabcentral/answers/439728-solving-a-system-of-ode-over-different-intervals-with-different-conditions-on-parameters#answer_356399 :
tPool = [0,1,2,4,8];
...
for k = 1:numel(tPool) - 1
    %                  ^^^
Concerning: "If I add the parameters Aap,Acp as input parameters of my anonymous function then I get: Not enough input arguments. Error in verysimple3>@(l,Tp,Aap,Acp)myODE(l,Tp,Aap,Acp)"
The ODE integrator calls the function to be integrated with 2 input arguments. The anonymous function is created to add further inputs. Therefore this works:
[l, Tp]=ode45(@(l,Tp) myODE(l,Tp,Aap,Acp),Pool(k:k+1),y0);
because here ODE45 provides the 2 inputs (l, Tp), the anonymous function appends 2 further inputs. With:
[l, Tp]=ode45(@(l,Tp,Aap,Acp) myODE(l,Tp,Aap,Acp), Pool(k:k+1), y0);
ODE45 is instructed to provide 4 inputs, but it can offer 2 only.
By the way, using "l" (lowercase L) as variable causes troubles freuqently, when it is confused with a "1" (one) or "I" (uppercase i).
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