atan2: Difference between revisions

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m (Text replacement - "\[\[Category:Scripting Commands OFP 1.[4-9]{2}(\|(\{\{uc:\{\{PAGENAME\}\}\}\}|#|[A-Z0-9]+))?\]\] " to "")
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{{RV|type=command
{{RV|type=command


| ofp
|game1= ofp
|version1= 1.00


|1.00
|game2= ofpe
|version2= 1.00
 
|game3= arma1
|version3= 1.00
 
|game4= arma2
|version4= 1.00
 
|game5= arma2oa
|version5= 1.51
 
|game6= tkoh
|version6= 1.00
 
|game7= arma3
|version7= 0.50


|gr1= Math - Geometry
|gr1= Math - Geometry


| ArcTangent of ''x/y''. Used to determine the angle of a vector ''[x,y]''. Result in [[Number#Degrees|Degrees]] between -180 and 180.
|descr= [[Image:atan.jpg|right|200px]] ArcTangent of ''x/y''. Used to determine the angle of a vector ''[x,y]''. Result in [[Number#Degrees|Degrees]] between -180 and 180.
<br><br>
{{Feature | Informative | This command can handle ''y'' being 0, unlike when using [[atan]], and will return 90 }}
{{Feature | Informative | This command can handle ''y'' being 0, unlike when using [[atan]], and will return 90 }}
<br>
{{Feature | important | Even though this command is a binary operator just like [[select]] command, it has [[SQF Syntax#Rules_of_Precedence | higher precedence]] than [[select]] command, therefore the following expression: <br><tt>_pos select 0 [[atan2]] (_pos select 1)</tt><br> will produce an error. The correct usage in this case will be: <br><tt>(_pos select 0) [[atan2]] (_pos select 1)</tt>}}
{{Feature | important | Even though this command is a binary operator just like [[select]] command, it has [[SQF Syntax#Rules_of_Precedence | higher precedence]] than [[select]] command, therefore the following expression: <br><tt>_pos select 0 [[atan2]] (_pos select 1)</tt><br> will produce an error. The correct usage in this case will be: <br><tt>(_pos select 0) [[atan2]] (_pos select 1)</tt>}}


| x '''atan2''' y
|s1= x [[atan2]] y


|p1=  x: [[Number]]
|p1=  x: [[Number]]
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|p2=  y: [[Number]]
|p2=  y: [[Number]]


| [[Number]]
|r1= [[Number]]
 
<br><br>[[Image:atan.jpg|200px]]
   
   
|x1= <code>_xy = [5,3];
|x1= <code>_xy = [5,3];
_degrees = (_xy [[select]] 0) [[atan2]] (_xy [[select]] 1); //59.0362</code>
_degrees = (_xy [[select]] 0) [[atan2]] (_xy [[select]] 1); {{cc|59.0362}}</code>


|x2= Get direction from _obj1 to _obj2:<code>_vd = [[getPosASL]] _obj2 [[vectorDiff]] [[getPosASL]] _obj1;
|x2= Get direction from _obj1 to _obj2:<code>_vd = [[getPosASL]] _obj2 [[vectorDiff]] [[getPosASL]] _obj1;
_dir = (_vd [[select]] 0) [[atan2]] (_vd [[select]] 1); //_dir range from -180 to +180  
_dir = (_vd [[select]] 0) [[atan2]] (_vd [[select]] 1); {{cc|_dir range from -180 to +180}}
[[if]] (_dir < 0) [[then]] {_dir = 360 + _dir}; //_dir range from 0 to 360</code>
[[if]] (_dir < 0) [[then]] {_dir = 360 + _dir}; {{cc|_dir range from 0 to 360}}</code>


|x3= Get relative direction from _obj1 to _obj2:<code>_xy = _obj1 [[worldToModel]] [[getPosASL]] _obj2;
|x3= Get relative direction from _obj1 to _obj2:<code>_xy = _obj1 [[worldToModel]] [[getPosASL]] _obj2;
_dir = (_xy [[select]] 0) [[atan2]] (_xy [[select]] 1); //_dir range from -180 to +180  
_dir = (_xy [[select]] 0) [[atan2]] (_xy [[select]] 1); {{cc|_dir range from -180 to +180}}
[[if]] (_dir < 0) [[then]] {_dir = 360 + _dir}; //_dir range from 0 to 360</code>
[[if]] (_dir < 0) [[then]] {_dir = 360 + _dir}; {{cc|_dir range from 0 to 360}}</code>


|seealso= [[atan]], [[tan]], [[sin]], [[cos]], [[asin]], [[acos]], [[rad]], [[pi]], [[vectorCos]], [[getPos]], [[getRelPos]], [[Math Commands]]
|seealso= [[atan]], [[tan]], [[sin]], [[cos]], [[asin]], [[acos]], [[rad]], [[pi]], [[vectorCos]], [[getPos]], [[getRelPos]], [[Math Commands]]
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<!-- Note Section END -->
<!-- Note Section END -->
</dl>
</dl>
{{GameCategory|arma1|Scripting Commands}}
{{GameCategory|arma2|Scripting Commands}}
{{GameCategory|arma3|Scripting Commands}}
{{GameCategory|tkoh|Scripting Commands}}

Revision as of 12:31, 1 April 2021

Logo A0.png1.00ofpe logo.png1.00Logo A1 black.png1.00Logo A2.png1.00A2 OA Logo.png1.51tkoh logo small.png1.00Arma 3 logo black.png0.50
Hover & click on the images for description

Description

Description:
atan.jpg
ArcTangent of x/y. Used to determine the angle of a vector [x,y]. Result in Degrees between -180 and 180.
ⓘ
This command can handle y being 0, unlike when using atan, and will return 90
⚠
Even though this command is a binary operator just like select command, it has higher precedence than select command, therefore the following expression:
_pos select 0 atan2 (_pos select 1)
will produce an error. The correct usage in this case will be:
(_pos select 0) atan2 (_pos select 1)
Groups:
Math - Geometry

Syntax

Syntax:
x atan2 y
Parameters:
x: Number
y: Number
Return Value:
Number

Examples

Example 1:
_xy = [5,3]; _degrees = (_xy select 0) atan2 (_xy select 1); // 59.0362
Example 2:
Get direction from _obj1 to _obj2:_vd = getPosASL _obj2 vectorDiff getPosASL _obj1; _dir = (_vd select 0) atan2 (_vd select 1); // _dir range from -180 to +180 if (_dir < 0) then {_dir = 360 + _dir}; // _dir range from 0 to 360
Example 3:
Get relative direction from _obj1 to _obj2:_xy = _obj1 worldToModel getPosASL _obj2; _dir = (_xy select 0) atan2 (_xy select 1); // _dir range from -180 to +180 if (_dir < 0) then {_dir = 360 + _dir}; // _dir range from 0 to 360

Additional Information

See also:
atantansincosasinacosradpivectorCosgetPosgetRelPosMath Commands

Notes

Report bugs on the Feedback Tracker and/or discuss them on the Arma Discord or on the Forums.
Only post proven facts here! Add Note
Posted on 08:00, 18 November 2009
KeV
To get the direction of an object from the player: _dir = ((getPos _obj select 0) - (getPos player select 0)) atan2 ((getPos _obj select 1) - (getPos player select 1)); //_dir will be from -180 to 180. If positive values are needed then use: if (_dir < 0) then {_dir = _dir + 360}; Or just use BIS_fnc_dirTo directly.
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