rowVar

语法

rowVar(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方差操作,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]);
$ rowVar(m);
[3.453333,2.173333,9.68]

$ 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);

$ rowVar(t1);
[22.333333,14.333333,8.333333,4.333333,2.333333]

$ rowVar(t1[`x], t2, 1 1 2 2 2);
[9.7,9.3,8.7,11,14.7]

$ 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,rowVar(price1,price2) as var from t;

sym

var

AAPL

7891.44845

MS

226.845

IBM

216.32

IBM

226.20645

C

11061.7938

相关函数: rowVarp, varp