Calculating Hessian without using symbolic functions

Is there a way to calculate the Hessian of a function that is not written as a symbolic function?

The function that I'm trying to calculate the Hessian for involves solving ordinary differential equations and cannot be easily written as a symbolic function.

Answer 1

[Walter Roberson]

No, not unless you can calculate it by hand ahead of time using some other set of external tools.

You can estimate the Hessian. See for example https://www.mathworks.com/matlabcentral/fileexchange/13490-adaptive-robust-numerical-differentiation