平面座標架
Author: 藍邦偉  老師

$ O $

$ u=Vector[(x(corner[1]),0),(x(corner[3]),0)]$
$v=Vector[(0,y(corner[1])),(0,y(corner[3]))]$

u = Vector((x(Corner[1]), 0), (x(Corner[3]), 0))
v = Vector((0, y(Corner[1])), (0, y(Corner[3])))
O = (0, 0)