ATN2 (Transact-SQL)

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) SQL analytics endpoint in Microsoft Fabric Warehouse in Microsoft Fabric

Returns the angle, in radians, between the positive x-axis and the ray from the origin to the point (y, x), where x and y are the values of the two specified float expressions.

Transact-SQL syntax conventions

ATN2 ( float_expression , float_expression )  

float_expression
An expression of data type float.

float

The following example calculates the ATN2 for the specified x and y components.

DECLARE @x FLOAT = 35.175643, @y FLOAT = 129.44;  
SELECT 'The ATN2 of the angle is: ' + CONVERT(VARCHAR, ATN2(@y, @x));  
GO  

Here's the result set.

The ATN2 of the angle is: 1.30545                         
(1 row(s) affected)  

CAST and CONVERT (Transact-SQL)
float and real (Transact-SQL)
Mathematical Functions (Transact-SQL)