在SQL中计算精​​度/召回曲线

Question

假设我有分类决策和信心作为记录，有没有办法通过SQL获得精确/召回曲线？换句话说，有没有办法将以下一组查询合并为一个？

select avg(predicted_label=correct_label) from t where confidence<0
select avg(predicted_label=correct_label) from t where confidence<1
select avg(predicted_label=correct_label) from t where confidence<2
select avg(predicted_label=correct_label) from t where confidence<3
select avg(predicted_label=correct_label) from t where confidence<4
select avg(predicted_label=correct_label) from t where confidence<5
select avg(predicted_label=correct_label) from t where confidence<6
....

Answer 1

要获得avg predicted_label的置信区间，请尝试这样做 编辑：在<=

上加入了

SELECT FLOOR(t1.confidence), AVG(t2.predicted_label)
FROM Table t1
    JOIN Table t2 ON t2.confidence <= t1.Confidence
GROUP BY FLOOR(t1.confidence)

Answer 2

如果您有一个表格（让我们称之为numbers的单列num）包含从0到足够大的数字的相关数字，那么您可以简单地说：

select avg(t.predicted_label=t.correct_label) 
  from t join numbers on t.confidence < numbers.num
 where numbers.num < 100 -- or whatever makes sense
group by numbers.num