rowStd

语法

rowStd(args...)

row 系列函数通用参数说明和计算规则请参考: 行计算系列(row 系列)

详情

逐行进行元素求样本标准差操作,返回一个长度与输入参数行数相同的向量。

例子

$ m=matrix([4.5 2.6 1.5, 1.5 4.8 5.9, 4.9 2.0 NULL])
$ rowStd(m);
[1.858315,1.474223,3.11127]

$ t1=table(1..5 as x, 10..6 as y, take(3, 5) as z)
$ t2=table(5..1 as a, 6..10 as b, take(8, 5) as c);

$ rowStd(t1);
[4.725816,3.785939,2.886751,2.081666,1.527525]

$ rowStd(t1[`x], t2, 1 1 2 2 2);
[3.114482,3.04959,2.949576,3.316625,3.834058]


$ t=table(`AAPL`MS`IBM`IBM`C as sym, 49.6 29.46 29.52 30.02 174.97 as price1, 175.23 50.76 50.32 51.29 26.23 as price2)
$ select sym,rowStd(price1,price2) as std from t;

sym

std

AAPL

88.833825

MS

15.061374

IBM

14.707821

IBM

15.040161

C

105.175063

相关函数: rowStdp, std