converting a multiple input function to a vector input function

My question is similar to this one

https://www.mathworks.com/matlabcentral/newsreader/view_thread/327273

I have a vector of symbolic expressions called "xdot_sym". Following the advice of the thread above I convert this function to a vector input function by the following

xdot_fun = matlabFunction(xdot_sym);

xdot_fun_vec = @(x) xdot_fun(x(1),x(2),x(3),x(4),x(5),x(6),x(7),x(8),x(9),x(10),x(11),x(12));

This works fine. However the length of my vector xdot_sym often changes. So I am looking for a way to define xdot_fun_vec for a variable number of input arguments (instead of just 12).

Answer 1

[Walter Roberson]

Read "Specify Input Arguments for Generated Function" in http://www.mathworks.com/help/symbolic/matlabfunction.html

So it would be like

matlabFunction(xdot_sym, {[p q s ...]})

where p q s ... is the list of variable names as they appear in xdot_sym; the first of them will be mapped to the first column of the single input, the second will be mapped to the second column of the single input, and so on.

[Trevor]

This works great although isn't it necessary to include 'Vars' in your example code?

[Walter Roberson]

Yes, 'Vars' would be needed,

matlabFunction(xdot_sym, 'Vars', {[p q s ...]})