Github user hequn8128 commented on a diff in the pull request:
https://github.com/apache/flink/pull/6223#discussion_r199537034
--- Diff: docs/dev/table/sql.md ---
@@ -1510,6 +1510,17 @@ ATAN(numeric)
</td>
</tr>
+ <tr>
+ <td>
+ {% highlight text %}
+ATAN2(numeric, numeric)
+{% endhighlight %}
+ </td>
+ <td>
+ <p>Calculates the arc tangent of a given coordinate.</p>
--- End diff --
I checked the [wiki](https://en.wikipedia.org/wiki/Atan2) about atan2, it
said: The atan2 function calculates one unique arc tangent value from two
variables y and x. So, would it be better `of two variables`? atan2(y,x) can
be the arc tangent of (x,y) or (nx, ny).
---
