# Defining integration function in matlanb

2 views (last 30 days)
Hannah Mohebi on 26 Feb 2022
Edited: Walter Roberson on 26 Feb 2022
I want to defin a fuction in matlab. This function is for calculating attached integral.
After defining this function I want to calculate H(T=100) in another m file.I wrote below function but it does not work.
function [H]=enthalpymethod(T)
H=int(Cp,T,[0 T]);
end

Walter Roberson on 26 Feb 2022
Edited: Walter Roberson on 26 Feb 2022
function [H]=enthalpymethod(T)
syms T
Cp = some expression in T
H(T) = vpaintegral(Cp,T,[0 T]);
end
Now when you invoke enthalpymethod it will return a symbolic function that you can do things like fplot(H) or H(100)
Note that this will typically be less efficient than if you were to use matlabFunction() to return an anonymous function that uses integral() to do the calculations. But if Cp involves any unresolved symbol variables other than T then you need a symbolic return

Alan Stevens on 26 Feb 2022
Like this?
% If Cp is a constant then the integral is just Cp*T
% If it is a function of T, then define the function:
Cp = @(T) 3 + T/100; % Arbitrary function - replace with your true function
H = integral(Cp,0,100);
disp(H)

R2020a

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