ATAN2 in Tableau: the SQL equivalent, with a worked example

ATAN2([score], [other])

id	amount	units	score	other
1	-2.5	2	-0.8	3
2	0	0	0	4
3	1.5	3	0.25	2
4	4	4	0.5	8
5	9	5	0.8	11
6	16	6	1	14
7	null	7	null	9
8	4	8	-0.5	null

SELECT atan2(score,other) AS result FROM input ORDER BY id

Runs the example above.

SELECT atan2(score,other) AS result FROM input ORDER BY id

Written for this dialect; not run here.

SELECT atan2(score,other) AS result FROM input ORDER BY id

Written for this dialect; not run here.

id	amount	units	score	result
1	-2.5	2	-0.8	-0.260602
2	0	0	0	0
3	1.5	3	0.25	0.124355
4	4	4	0.5	0.0624188
5	9	5	0.8	0.0725995
6	16	6	1	0.0713075
7	null	7	null	null
8	4	8	-0.5	null

Same rows from the calculation and from the SQL in DuckDB.

Where a naive translation goes wrong

Replacing null results with zero changes missing-value semantics.
Naive SQL
```
SELECT coalesce((atan2(score,other)),0) AS result FROM input ORDER BY id
```
id amount units score result
1 -2.5 2 -0.8 -0.260602
2 0 0 0 0
3 1.5 3 0.25 0.124355
4 4 4 0.5 0.0624188
5 9 5 0.8 0.0725995
6 16 6 1 0.0713075
7 null 7 null 0
8 4 8 -0.5 0
Matches the calculation
```
SELECT atan2(score,other) AS result FROM input ORDER BY id
```
id amount units score result
1 -2.5 2 -0.8 -0.260602
2 0 0 0 0
3 1.5 3 0.25 0.124355
4 4 4 0.5 0.0624188
5 9 5 0.8 0.0725995
6 16 6 1 0.0713075
7 null 7 null null
8 4 8 -0.5 null

ATAN2(number, number)