tmkurtosis

tmkurtosis(T, X, window, [biased=true])

部分通用参数说明和窗口计算规则请参考：tmFunctions

biased 是一个布尔值，表示是否是有偏估计。默认值为 true，表示有偏估计。

在给定长度（以时间 T 衡量）的滑动窗口内计算 X 的峰度。

T = 1 1 1 2 5 6
X = 1 4 NULL -1 NULL 4
m = table(T as t, X as x)
select *, tmkurtosis(t, x, 3) from m

T = take(datehour(2019.06.13 13:30:10),4) join (datehour(2019.06.13 13:30:10)+1..6)
X = 1 NULL 3 4 5 NULL 3 NULL 5 3
m = table(T as t,X as x)
select *, tmkurtosis(t, x, 3d) from m

select *, tmkurtosis(t, x, 1w) from m

相关函数：mkurtosis, kurtosis