atan2

Typefunction
DictionaryLCS
LibraryLiveCode Script
Syntax
atan2(<yCoordinate>, <xCoordinate>)
Summary

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

Introduced1.0
OSmac, windows, linux, ios, android
Platformsdesktop, server, mobile
Parameters
NameTypeDescription
yCoordinate

A number or an expression that evaluates to a number.

xCoordinate

A number or an expression that evaluates to a number.

Example
atan2(-1,-1) -- returns 4/3 * pi
atan2(thisNumber,thatNumber)
Values
NameTypeDescription
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
RelatedConstant: pi
Glossary: sign, radian, custom function, return, degree, math operation
Control Structure: function
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.

Tagsmath