Derivative a function according to another function

Hello

This is my code :

t= sym('t');
y(t)=sym('y(t)');
%Then i do some calculation but let's say that 
T= 1/2*y(t)^2 %this is not my function but an exemple.

I try to differentiate T according to y. I try diff(T,y) and diff(T,y(t)), both don't work.

Do you have any clue how to do that ?

Thanks

Answer 1

[Mischa Kim]

Alexis, I believe functionalDerivative is what you are looking for:

 t    = sym('t');
 y(t) = sym('y(t)');

 T    = 1/2*y(t)^2;

 functionalDerivative(T,y)
 ans(t) =
 y(t)