matlab初学之roundn和round
⽂章出处：
a=123.4567890;
round函数怎么使用matlaba=roundn(a,-4)
% 返回 123.4568
Round numbers to specified power of 10
函数简介
  调⽤格式：Y = round(X)
  在matlab中round也是⼀个四舍五⼊函数。在matlab的命令窗⼝中输⼊doc round或者help round即可获得该函数的相关帮助信息。  相关函数：ceil、floor、fix
程序⽰例
  >>a = [-1.9, -0.2, 3.4, 5.6, 7.0, 2.4+3.6i]
  a =
  Columns 1 through 4
  -1.9000 -0.2000 3.4000 5.6000
  Columns 5 through 6
  7.0000 2.4000 + 3.6000i
  >>round(a)
  ans =
  Columns 1 through 4
  -2.0000 0 3.0000 6.0000
  Columns 5 through 6
  7.0000 2.0000 + 4.0000i
  a =
  Columns 1 through 4
  -1.9000 -0.2000 3.4000 5.6000
  Columns 5 through 6
  7.0000 2.4000 + 3.6000i