比较账单税前利润和税前金额的总体协方差和样本协方差
总体协方差和样本协方差的对比 用 time_series 函数聚合时间,然后用 covar_pop 函数计算总体协方差,用 covar_samp 函数计算样本协方差 用线图展示
SQL
source :bill |
select
covar_samp(PretaxGrossAmount, PretaxAmount) as "样本协方差",
covar_pop(PretaxGrossAmount, PretaxAmount) as "总体协方差" ,
time_series(__time__, '1m', '%H:%i:%s', '0') as time GROUP BY time