Evaluate a vectorial symbolic matlab function through Matrices and vectors directly

Hello everyone,

I'm actually working with the symbolic toolbox, and I want to evaluate a matlab symbolic function that depends on a matrix and a vector which the dimension changes in the general application.

However, when I want to evaluate the final result, the error message tells me that I have to pass on the members of the matrix and the vector, and it is exactly the thing that I want to avoid.

clear;close;clc;

Msym    =  sym('M', [8, 2], 'real');
vsym    =  sym('v', [2, 1], 'real');
q0sym   =  sym('q0', [8, 1], 'real');

qsym    =  Msym * vsym + q0sym; 

q0  =  [0; 0; 0; 1; 0; 0; 0; 1];
M   =  [0, 0; 0.0164, 0.0109; 0, 0; -0.0005, -0.0005; 0, 0; 0, 0.0553; 0, 0; 0, -0.0011];
v   =  [0; 0];

q = matlabFunction(qsym)

q_eval = double(q(q0, M, v))

Can anyone help me please to solve this probem ?

P.S: I have already succeeded to solve this problem using "subs", but it is taking long time when the size of Msym and vsym are great.

Thanks in advance.

Answer 1

[Ameer Hamza]

The function handle is not being created in the way you want. Change the matlabFunction line to

q = matlabFunction(qsym, 'Vars', {q0sym, Msym, vsym})

[Ameer Hamza]

The variables are not attached. Can you attach them in a .mat file?