def Hex8_node_coords(n): #Test function written
    """Get the local coordinates for node n (0-7)"""
    coords = [[-1,-1,-1],[ 1,-1,-1],[ 1, 1,-1],[-1, 1,-1],\
              [-1,-1, 1],[ 1,-1, 1],[ 1, 1, 1],[-1, 1, 1]]
    return coords[n]