﻿功能:求数据的标准差

格式: DataStdDev(a)

a : 为存储样本数据的矩阵变量

说明: 
1. 本函数执行成功返回a的标准差, 求标准差时, 对除数, 整体个数会减去1
2. DataStdDev(a) = {Sqrt<矩阵运算\Sqrt>}({DataVar<矩阵运算\DataVar>}(a))
3. DataStdDev(a) = {Sqrt<矩阵运算\Sqrt>}({Sum<矩阵运算\Sum>}((a - {DataMean<矩阵运算\DataMean>}(a))^2) / ({Length<矩阵运算\Length>}(a) - 1))

例子:
a =
[ 6.33104550481357    9.30321055432000    0.18615803224321    7.71025022850849
  8.04941486476428    1.83635290797630    8.88352177519515    6.59557374967056
  2.84064090942994    2.11438811948262    1.34344469352786    1.19332172497796
  5.49156385729628    7.50859408057695    4.16200918804948    8.83863473256986 ]
b = DataStdDev(a)//回车得到a的标准差
b =
[ 3.16448402244721 ]