A partially complete MATLAB function m file is shown for computing the element stiffness matrix for a four-noded quadrilateral clement. Write out the six missing lines of MATLAB code. (13 Marks) function estice stitips (node, ndime, nevab, ngaus, lelem, inods, coord, young poiss, thick) 3 Initialise stiffness matrix estiti nevab, 1:nevab) = $ Set integration positions and weights [posgp, weigpl - gaussa Set element local coords eleod ( from global coordinates coord for in 1:nnode Missing code line 1 end Enter Gauss integration loop for igaus-i:ngaus: Set local coordinates xi and eta at the current gauss point position Missing code line 2 (2 statements) Shape functions, derivatives, Jacobian, elemental volume Ishape, deriv]-shapes (xi,etal ac, jaci, dets, cartd) - Jacob (ndime, nnode, elcod, xi, eta, shape, derivi: Missing code line 3 B and D matrices dmatx-amatps young, poiss)! bmatx-bmatps (ndime, nnode, cartd Form DB matrix and element stiftness matrix Missing code linea Missing code line 5 Missing code line 6 end [25 Marks for 03] A partially complete MATLAB function m file is shown for computing the element stiffness matrix for a four-noded quadrilateral clement. Write out the six missing lines of MATLAB code. (13 Marks) function estice stitips (node, ndime, nevab, ngaus, lelem, inods, coord, young poiss, thick) 3 Initialise stiffness matrix estiti nevab, 1:nevab) = $ Set integration positions and weights [posgp, weigpl - gaussa Set element local coords eleod ( from global coordinates coord for in 1:nnode Missing code line 1 end Enter Gauss integration loop for igaus-i:ngaus: Set local coordinates xi and eta at the current gauss point position Missing code line 2 (2 statements) Shape functions, derivatives, Jacobian, elemental volume Ishape, deriv]-shapes (xi,etal ac, jaci, dets, cartd) - Jacob (ndime, nnode, elcod, xi, eta, shape, derivi: Missing code line 3 B and D matrices dmatx-amatps young, poiss)! bmatx-bmatps (ndime, nnode, cartd Form DB matrix and element stiftness matrix Missing code linea Missing code line 5 Missing code line 6 end [25 Marks for 03]