import { Mean } from "./Mean" ; /**
 * 方差的正平方根称为该随机变量的标准差
 * 方差
 */ function Variance ( [ ... value ] ) { var mean = Mean ( [ ... value ] ) ; var total = 0 ; for ( let i = 0 ; i < value . length - 1 ; i ++ ) { total += Math . pow ( ( value [ i ] - mean ) , 2 ) ; } return total / value . length ; } export { Variance } ;