atan2: Difference between revisions

Latest revision as of 09:38, 25 March 2024

1.00

1.50

1.00

0.50

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Description

Description:: ArcTangent of y/x. Used to determine the angle of a vector [y,x]. Result in Degrees between -180 and 180.
ⓘ
This command can handle x being 0, unlike when using atan, and will return 90

⚠
This command has higher precedence than the select command, therefore beware of the case below:
_pos select 0 atan2 (_pos select 1) // error (_pos select 0) atan2 (_pos select 1) // OK

Alternatively, consider using the # operator: _pos # 0 atan2 _pos # 1
Groups:: Math - Geometry

Syntax

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

Examples

Example 1:: _yx = [5,3]; _degrees = (_yx select 0) atan2 (_yx 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 _dir = (_dir + 360) % 360; // _dir range from 0 to 360
Example 3:: Get relative direction from _obj1 to _obj2:
_yx = _obj1 worldToModel getPosASL _obj2; _dir = (_yx select 0) atan2 (_yx select 1); // _dir range from -180 to +180 _dir = (_dir + 360) % 360; // _dir range from 0 to 360

Additional Information

See also:: atan tan sin cos asin acos rad pi vectorCos BIS_fnc_dirTo getRelPos getRelDir

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

@@ Line 1: / Line 1: @@
 {{RV|type=command
-| ofp
+|game1= ofp
+|version1= 1.00
-|1.00
+|game2= ofpe
+|version2= 1.00
-|gr1= Math - Geometry
+|game3= arma1
+|version3= 1.00
+|game4= arma2
+|version4= 1.00
+|game5= arma2oa
+|version5= 1.50
+|game6= tkoh
+|version6= 1.00
-| ArcTangent of ''x/y''. Used to determine the angle of a vector ''[x,y]''. Result in [[Number#Degrees|Degrees]] between -180 and 180.
+|game7= arma3
-<br><br>
+|version7= 0.50
-{{Informative | This command can handle ''y'' being 0, unlike when using [[atan]], and will return 90 }}
-<br>
-{{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
+|gr1= Math - Geometry
-|p1=  x: [[Number]]
+|descr= [[File:atan.jpg|right|300px]] ArcTangent of ''y/x''. Used to determine the angle of a vector ''[y,x]''. Result in [[Number#Degrees|Degrees]] between -180 and 180.
+{{Feature|informative|This command can handle ''x'' being 0, unlike when using [[atan]], and will return 90}}
+{{Feature|important|
+This command has [[SQF Syntax#Rules of Precedence|higher precedence]] than the [[select]] command, therefore beware of the case below:
+<sqf notrim>
+ _pos select 0  atan2 (_pos select 1) // error
+(_pos select 0) atan2 (_pos select 1) // OK
+</sqf>
-|p2=  y: [[Number]]
+Alternatively, consider using the [[a hash b|#]] operator: <sqf inline>_pos # 0 atan2 _pos # 1</sqf>
+}}
-| [[Number]]
+|s1= y [[atan2]] x
-<br><br>[[Image:atan.jpg|200px]]
+|p1= y: [[Number]]
-|x1= <code>_xy = [5,3];
-_degrees = (_xy [[select]] 0) [[atan2]] (_xy [[select]] 1); //59.0362</code>
-|x2= Get direction from _obj1 to _obj2:<code>_vd = [[getPosASL]] _obj2 [[vectorDiff]] [[getPosASL]] _obj1;
+|p2= x: [[Number]]
-_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</code>
-|x3= Get relative direction from _obj1 to _obj2:<code>_xy = _obj1 [[worldToModel]] [[getPosASL]] _obj2;
+|r1= [[Number]]
-_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</code>
-| [[atan]], [[tan]], [[sin]], [[cos]], [[asin]], [[acos]], [[rad]], [[pi]], [[vectorCos]], [[getPos]], [[getRelPos]], [[Math Commands]]
+|x1= <sqf>
-}}
+_yx = [5,3];
+_degrees = (_yx select 0) atan2 (_yx select 1); // 59.0362
+</sqf>
-<dl class="command_description">
+|x2= Get direction from _obj1 to _obj2:
-<!-- Note Section BEGIN -->
+<sqf>
-<dd class="notedate">Posted on 08:00, 18 November 2009</dd>
+_vd = getPosASL _obj2 vectorDiff getPosASL _obj1;
-<dt class="note">[[User:KeV|KeV]]<dd class="note">
+_dir = (_vd select 0) atan2 (_vd select 1); // _dir range from -180 to +180
-To get the direction of an object from the player:
+_dir = (_dir + 360) % 360; // _dir range from 0 to 360
-<code>
+</sqf>
-_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.
-</code>
-If positive values are needed then use:
-<code>
-[[if]] (_dir < 0) [[then]] {_dir = _dir + 360};
-</code>
-Or just use [[BIS_fnc_dirTo]] directly.
-<!-- Note Section END -->
-</dl>
+|x3= Get relative direction from _obj1 to _obj2:
+<sqf>
+_yx = _obj1 worldToModel getPosASL _obj2;
+_dir = (_yx select 0) atan2 (_yx select 1); // _dir range from -180 to +180
+_dir = (_dir + 360) % 360; // _dir range from 0 to 360
+</sqf>
-[[Category:Scripting Commands|ATAN2]]
+|seealso= [[atan]] [[tan]] [[sin]] [[cos]] [[asin]] [[acos]] [[rad]] [[pi]] [[vectorCos]] [[BIS_fnc_dirTo]] [[getRelPos]] [[getRelDir]]
-[[Category:Scripting Commands OFP 1.99|ATAN2]]
+}}
-[[Category:Scripting Commands OFP 1.96|ATAN2]]
-[[Category:Scripting Commands OFP 1.46|ATAN2]]
-{{GameCategory|arma1|Scripting Commands}}
-{{GameCategory|arma2|Scripting Commands}}
-{{GameCategory|arma3|Scripting Commands}}
-{{GameCategory|tkoh|Scripting Commands}}

atan2: Difference between revisions

Latest revision as of 09:38, 25 March 2024

Description

Syntax

Examples

Additional Information

Notes

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