How can I arrange the global stiffness matrix of a 2D finite elements with each square or rectangle made of different materials?

Each of the squares or rectangular elements is made of different materials with different Young's Modulus (see the picture below). I can compute the 8 x 8 stiffness matrix for each of the elements. But I need a MATLAB code I can use to compute the global stiffness matrix and calculate the displacements on each node if I apply force as boundary condition.

Answer 1

[Areeb Siraj]

Can u link your code below. It help in better understanding it.