atan2

Type

function

Summary

Returns the arc tangent of one number divided by another, using the sign of both.

Syntax

atan2(<yCoordinate>, <xCoordinate>)

Description

Use the atan2 function to find the arc tangent of one number divided by another when sign is significant.

In most cases, atan2(y,x) is equal to atan(y/x). However, if both x and y are negative, the sign of x/y is positive. In this case, the atan function returns an angle in the first quadrant, but the atan2 function returns an angle in the third quadrant.

If a math operation on finite inputs produces a non-finite output, an execution error is thrown. See math operations for more information.

Parameters

Name	Type	Description
yCoordinate		A number or an expression that evaluates to a number.
xCoordinate		A number or an expression that evaluates to a number.

Examples

atan2(-1,-1) -- returns 4/3 * pi

atan2(thisNumber,thatNumber)

Value

Name	Type	Description
return		The atan2 function returns a number between -pi and pi.
the result		The result of the atan2 function is returned in radians. To get this result in degrees, use the following custom function: function atan2InDegrees pFirstArg,pSecondArg return atan2(pFirstArg,pSecondArg) * 180 / pi end atan2InDegrees

Related

constant: pi

control structure: function

glossary: sign, radian, custom function, return, degree, math operation

Compatibility and Support

Introduced

LiveCode 1.0

OS

mac

windows

linux

ios

android

Platforms

desktop

server

mobile