def METHOD_NAME(Map,aM=0.5,aN=0.5):
	"""
	Produce scalar interpolation matrix Wvc for state-space realisation.
	Important: this will not work for coordinates extrapolation, as it would
	require information about the panel size. It works for other forces/scalar 
	quantities extrapolation. It assumes the quantity at the collocation point
	is determined proportionally to the weight associated to each vertex and 
	obtained through get_panel_wcv. 
	"""
	# initialise
	K,Kzeta=Map.K,Map.Kzeta
	Wvc=np.zeros((Kzeta,K))
	# retrieve weights
	wcv=get_panel_wcv(aM,aN)
	wvc=wcv.T
	# define mapping panels to vertices (for scalars)
	if not hasattr(Map,'Mvp1d_scalar'):
		Map.map_panels_to_vertices_1D_scalar()
	# loop through panels
	for jj in range(K):
		# loop through local vertex index
		for vv in range(4):
			# vertex 1d index
			ii = Map.Mpv1d_scalar[jj,vv]
			# allocate
			Wvc[ii,jj]=wvc[vv]
	return Wvc