Use a symfun as index of a matrix

Hi everybody, I have a notation problem.

syms f(t) g(t)

v lxmxn 3d matrix

I am to write an equation like:

eq = diff(f) == v(f(t),g(t),t)

but i get a sym/subsindex error.

how can I access elements of a matrix indexed by a function?

Answer 1

[amin ya]

use formula to convert symfun to a matrix:

matrix=formula()