Hey Dheeraj,
As per my understanding, you are trying to write a matlab script which can extract coefficients from the ODEs given by you and form a state space matrix.
Instead of manually collecting terms from these equations, you can employ MATLAB's symbolic computation capabilities. you can use the 'coeffs' function, which automatically extracts coefficients from the equations of motion. This function takes a set of equations and a set of variables as inputs, and it returns the coefficients of those variables in the equations. Please refer to the following link to go through the detailed documentation of this function.
Once you have the coefficients extracted, you can construct the mass, damping, and stiffness matrices by arranging these coefficients into the appropriate positions in the matrices. you can accomplish this using nested loops to iterate over the coefficients and fill in the matrices accordingly.
Hope this helps!
