cumavgTopN
Syntax
cumavgTopN(X, S, top, [ascending=true], [tiesMethod=’latest’])
Please see Cumulative Moving TopN Functions (cumTopN functions) for the parameters and windowing logic.
Details
After stably sorting S in the specified ascending order, the function calculates the average of the first top elements of X in a cumulative window.
Return value: DOUBLE type.
Examples
$ X=1 2 3 10 100 4 3
$ S = 0.3 0.5 0.1 0.1 0.5 0.2 0.4
$ cumavgTopN(X, S, 6, 4)
[1,1.5,2,4,23.199,20,20.167]
$ X = matrix(1..10, 11..20)
$ S = matrix(2022.01.01 2022.02.03 2022.01.23 NULL 2021.12.29 2022.01.20 2022.01.23 2022.01.22 2022.01.24 2022.01.24, NULL 2022.02.03 2022.01.23 2022.04.06 NULL 2022.02.03 2022.02.03 2022.02.05 2022.02.08 2022.02.03)
$ cumavgTopN(X, S, 6, 4)
#0 |
#1 |
|---|---|
1 |
|
1.5 |
12 |
2 |
12.5 |
2 |
13 |
2.75 |
13 |
3.4 |
13.75 |
4 |
14.4 |
5 |
15 |
5 |
15.8333 |
5 |
16 |
$ id=rand(10,10)
$ price=rand(100,10)
$ t=table(id, price)
$ select cumavgTopN(price, id, 6, 4) as result from t
result |
|---|
94 |
69.5 |
46.3333 |
55.75 |
57.8 |
49.6667 |
50.5 |
50.5 |
51.5 |
51.5 |