ODE45 error must return column vector
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No matter what I do I keep receiving the error of a column vector. I have tried making it all zeros first befort completing the function to create a column vector but nothing is working. Any insight would be helpful.
CO(2,1) = 10;
tRange(2,1) = 10;
[tSol,CSol] = ode45(@ConvFunction,tRange,CO);
plot(tSol,CSol(:,1))
function F = ConvFunction(t,~)
CaO=10;
k1=.45;
k2=.05;
Ca=CaO*exp(-t*(k1+k2));
dCadt=-(k1*(Ca)-(k2*(Ca)));
dCbdt=k1*(Ca);
dCcdt=k2*(Ca);
dFdt = zeros(3,1);
dFdt = [dCadt dCbdt dCcdt];
F= dFdt;
end
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Accepted Answer
Paul
on 11 Mar 2023
Try doing what the error message says and make sure that F is a column vector. Here's one option
dFdt = [dCadt ; dCbdt ; dCcdt];
Also, the code is only specifying two initial conditions. It needs to specify three.
2 Comments
Walter Roberson
on 11 Mar 2023
Unless you have assigned something to CO before this,
CO(2,1) = 10;
creates CO as a column vector with exactly two values. You are passing that vector of length 2 as the initial state. You ignore the state inside ConvFunction and return a vector of length 3 . The length of the vector you return must be the same as the number of input values.
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