floor:朝负无穷方向舍入 b = floor(a) ro nds the elements of a to the nearest integers less than or eq al to a. ceil:朝正无穷方向舍入 b = ceil(a) ro nds the elements of a to the nearest integers greater than or eq al to a. fix:朝零方向舍入 b = fix(a) ro nds the elements of a toward zero, res lting in an array of integers. ro nd:四舍五入 b = ro nd(a) ro nds the elements of x to the nearest integers. norm:求矩阵或向量的泛数 x = [1 2 3 4 5 6]; norm(x) = 9.5394 example: a= [-0.9, -2.1, -0.4, 0.3, 0.8, 1.1, 2.7, -1.2+2.9i]; floor(a)=[ -1, -3, -1, 0, 0, 1, 2, -2+2i] ceil(a)= [ 0, -2, 0, 1, 1, 2, 3, -1+3i] fix(a)= [ 0, -2, 0, 0, 0, 1, 2, -1+2i] ro nd(a)=[-1, -2, 0, 0, 1, 1, 3, -1+3i] 注:for complex x, for all the fo r f ctions the imaginary and real parts are ro nded independently.