sumbars
Syntax
sumbars(X, Y)
Arguments
X is a vector/tuple/matrix/table whose elements must be non-negative numbers.
Y is a vector/scalar.
If X is a vector, Y is a scalar.
If X is a tuple, Y is a vector with the same length as X.
If X is a matrix/table, Y is a vector with the same length as the number of columns of X.
Details
For each element X i in X, calculate the cumulative sum of X i in the backward direction, i.e., (X i + X i-1 + X i-2 …), until the value is no smaller than Y.
If the cumulative sum never exceeds Y, return 0.
Examples
$ sumbars(1 2 3.3 2 5, 3)
[0,2,1,2,1]
$ sumbars(matrix(5 3 6 2 3, 2 6 1 5 4), [5, 8])
col1 |
col2 |
|---|---|
1 |
0 |
2 |
2 |
1 |
3 |
2 |
3 |
2 |
2 |
// calculate the turnover period
$ id = `A`A`B`A`C`B`A`C`A`B
$ time = 2022.01.01T09:00:00 + 0..9
$ volume = 100 150 80 120 220 200 180 90 100 125
$ t = table(id, time, volume)
$ capital = 300
$ re = select *, sumbars(volume, capital) as period from t
$ re;
id |
time |
volume |
period |
|---|---|---|---|
A |
2022.01.01T09:00:00 |
100 |
0 |
A |
2022.01.01T09:00:01 |
150 |
0 |
B |
2022.01.01T09:00:02 |
80 |
3 |
A |
2022.01.01T09:00:03 |
120 |
3 |
C |
2022.01.01T09:00:04 |
220 |
2 |
B |
2022.01.01T09:00:05 |
200 |
2 |
A |
2022.01.01T09:00:06 |
180 |
2 |
C |
2022.01.01T09:00:07 |
90 |
3 |
A |
2022.01.01T09:00:08 |
100 |
3 |
B |
2022.01.01T09:00:09 |
125 |
3 |