短語詞組短語mobile unit identity vector 移動單元鑒別矢量unit cell vector detail 點陣矢unit coordinate vector [數(shù)]單位坐標(biāo)向量variable unit -vector 可變單位向量discrete unit normal vector 離散單位法向量unit cell vector 點陣矢unit tangent vector [數(shù)]單位切向量outward unit normal vector 外向單位法向向量unit of vector 向量單位 返回 unit vector