ATAN

A function that calculates the inverse tangent (arc tangent). expr is a real number representing radians (not degrees).

Syntax

ATAN(expr)

Argument

expr: A real number or an argument of another data type that can be converted to a numeric data type.

Return Value

A DECIMAL value in radians (not degrees) in the range [-π, +π], corresponding to the arc tangent value of the argument.

Example

SELECT atan(NULL), atan(0), atan('0'), atan(1), atan(acos(-1));

+-------------+-------------+-------------+-------------+----------------+
|  ATAN(NULL) |   ATAN(0)   |  ATAN('0')  |   ATAN(1)   | ATAN(ACOS(-1)) |
|-------------+-------------+-------------+-------------+----------------|
|        NULL |           0 |           0 |       ~0.79 |          ~1.26 |
+-------------+-------------+-------------+-------------+----------------+