atn2-transact-sql.md

title	ATN2 (Transact-SQL) | Microsoft Docs
ms.custom
ms.date	07/24/2017
ms.prod	sql
ms.prod_service	database-engine, sql-database, sql-data-warehouse, pdw
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ms.technology	t-sql
ms.topic	language-reference
f1_keywords	ATN2 ATN2_TSQL
dev_langs	TSQL
helpviewer_keywords	arctangent tangent ATN2 function
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author	MashaMSFT
ms.author	mathoma
manager	craigg
monikerRange	>=aps-pdw-2016||=azuresqldb-current||=azure-sqldw-latest||>=sql-server-2016||=sqlallproducts-allversions||>=sql-server-linux-2017||=azuresqldb-mi-current

ATN2 (Transact-SQL)

[!INCLUDEtsql-appliesto-ss2008-all-md]

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

Syntax

ATN2 ( float_expression , float_expression )  

Arguments

float_expression
An expression of data type float.

Return types

float

Examples

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  

[!INCLUDEssResult]

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

See also

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