def METHOD_NAME(self, uh, bc):
    gradphi = self.grad_basis(bc)
    cell2dof = self.cell_to_dof()
    NC = self.mesh.number_of_cells()
    val = np.zeros((NC,2), dtype=self.dtype)
    val[:,0]= (uh[cell2dof]*gradphi[:,:,0]).sum(axis=1)
    val[:,1]= (uh[cell2dof]*gradphi[:,:,1]).sum(axis=1)
    return val