你有一个抽样问题。他们解决这个问题的关键是将数据分成三个变量组合的单独组。然后,计算每个组的边际概率的乘积(您的值是边际概率)。然后,对所有 18 个组进行标准化。
例如,Male-Young-Low 组将获得 0.5*0.3*0.4 = 0.06 的值。您对所有 18 个组重复此操作,然后标准化为百分比(即,将每个值除以所有值的总和)。结果如下:
Gender Age Income Marg Normalized
Male Young Low 0.06 5.5%
Male Young Middle 0.06 5.5%
Male Young High 0.03 2.7%
Male Middle Low 0.08 7.3%
Male Middle Middle 0.08 7.3%
Male Middle High 0.04 3.6%
Male Old Low 0.08 7.3%
Male Old Middle 0.08 7.3%
Male Old High 0.04 3.6%
Female Young Low 0.06 5.5%
Female Young Middle 0.06 5.5%
Female Young High 0.03 2.7%
Female Middle Low 0.08 7.3%
Female Middle Middle 0.08 7.3%
Female Middle High 0.04 3.6%
Female Old Low 0.08 7.3%
Female Old Middle 0.08 7.3%
Female Old High 0.04 3.6%
然后这将成为每个组的采样率。这是实际进行采样的伪 SQL 代码:
with SamplingRates (
select 'Male' as gender, 'Young' as Age, 'Low' as income, 0.045 as SamplingRate,
union all . .
)
select t.*
from (select t.*,
row_number() over (partition by gender, age, income order by <random>) as seqnum,
count(*) over (partition by gender, age, income) as NumRecs
from table t
) t join
SampleRates sr
on t.gender = sr.gender and t.age = sr.age and t.income = sr.income and
seqnum <= sr.SamplingRate * NumRecs