random: Difference between revisions

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{{Command|= Comments
{{Command|Comments=
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| ofp |= Game name
| ofp |Game name=


|1.00|= Game version
|1.00|Game version=
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|[[Image:bellcurve.jpg|right|200px]] Random real (floating point) value from 0 (inclusive) to x (not inclusive).<br><br>
|[[Image:bellcurve.jpg|right|200px]] Random real (floating point) value from 0 (inclusive) to x (not inclusive).<br />
Since Arma 3 v1.55.133393 alternative syntax is added, allowing to define [https://en.wikipedia.org/wiki/Normal_distribution Gaussian Distribution] params. Uses the same method as [[setTriggerTimeout]] command. Quite useful for spawning loot for example, making more valuable items more rare.<br><br>
<br />
Since Arma 3 v1.67.139663 an alternative syntax is available, allowing to generate semi-random number based on provided seed.<br><br>
Since Arma 3 v1.55.133393 alternative syntax is added, allowing to define [https://en.wikipedia.org/wiki/Normal_distribution Gaussian Distribution] params. Uses the same method as [[setTriggerTimeout]] command. Quite useful for spawning loot for example, making more valuable items more rare ('''Alternative Syntax 1''')<br /><br />
Since Arma 3 v1.67.139663 an alternative syntax is available, generating pseudo-random [https://en.wikipedia.org/wiki/Perlin_noise noise texture] based on provided seed and returning a single number between 0 (included) and 1 (excluded) at supplied ''x'' and ''y'' coordinates. |= Description
Since Arma 3 v1.67.139663 two alternative syntaxes are available:
 
* allowing to generate semi-random number based on provided seed ('''Alternative Syntax 2''')
* generating pseudo-random [https://en.wikipedia.org/wiki/Perlin_noise noise texture] based on provided seed and returning a single number between 0 (included) and 1 (excluded) at supplied ''x'' and ''y'' coordinates ('''Alternative Syntax 3''') |Description=
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|'''random''' x |= Syntax
| [[random]] x |Syntax=
|p1= x: [[Number]]
|p1= x: [[Number]]
| [[Number]] |= Return value
| [[Number]] |Return value=


|s2= '''random''' [min, mid, max] &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(''Since Arma 3 v1.55.133393'')|= Syntax
|s2= [[random]] [min, mid, max] &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(''Since Arma 3 v1.55.133393'')|Syntax 2=
|p21= [min, mid, max]: [[Array]] |=
|p21= [min, mid, max]: [[Array]] |Parameter 21=
|p22= min: [[Number]] |=
|p22= min: [[Number]] |Parameter 22=
|p23= mid: [[Number]] |=
|p23= mid: [[Number]] |Parameter 23=
|p24= max: [[Number]] |=
|p24= max: [[Number]] |Parameter 24=
|r2= [[Number]] |= Return value
|r2= [[Number]] |Return value 2=


|s3= seed '''random''' x &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(''Since Arma 3 v1.67.139663'')|= Syntax
|s3= seed [[random]] x &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(''Since Arma 3 v1.67.139663'')|Syntax 3=
|p41= seed: [[Number]] |=
|p41= seed: [[Number]] |Parameter 41=
|p42= x: [[Number]] |=
|p42= x: [[Number]] |Parameter 42=
|r3= [[Number]] |= Return value
|r3= [[Number]] |Return value 3=
 
|s4= seed '''random''' [x,y] &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(''Since Arma 3 v1.67.139663'') |= Syntax
|p61= seed: [[Number]] |=
|p62= [x, y]: [[Array]] |=
|p63= x: [[Number]] |=
|p64= y: [[Number]] |=
|r4= [[Number]] |= Return value


|s4= seed [[random]] [x, y] &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(''Since Arma 3 v1.67.139663'') |Syntax 4=
|p61= seed: [[Number]] |Parameter 61=
|p62= [x, y]: [[Array]] position on the [https://en.wikipedia.org/wiki/Perlin_noise Perlin noise texture] |Parameter 62=
|p63= x: [[Number]] |Parameter 63=
|p64= y: [[Number]] |Parameter 64=
|r4= [[Number]] |Return value 4=
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|x1= <code>_rNumber = [[random]] 1;</code> |= Example 1
|x1= <code>_rNumber = [[random]] 1;</code> |Example 1=


|x2= <code>_rNumber = [[random]] -10;</code> |= Example 2
|x2= <code>_rNumber = [[random]] -10;</code> |Example 2=


|x3= Generate random position inside a circle<code>_center [[getPos]] <nowiki>[</nowiki>_radius * [[sqrt]] [[random]] 1, [[random]] 360];</code> |= Example 2
|x3= Generate random position inside a circle
<code>_center [[getPos]] <nowiki>[</nowiki>_radius * [[sqrt]] [[random]] 1, [[random]] 360];</code> |Example 3=


|x4= To select random value from an array:
|x4= To select random value from an array:
<code>_array = ["apples", "pears", "bananas", "M16"];
<code>_array = ["apples", "pears", "bananas", "M16"];
_random = _array [[select]] [[floor]] [[random]] [[count]] _array;
_random = _array [[select]] [[floor]] [[random]] [[count]] _array;
// or since Arma 3 v1.55.133393
{{codecomment|// since Arma 3 v1.55.133393}}
_random = [[selectRandom]] _array;</code>  |= Example 3
_random = [[selectRandom]] _array;</code>  |Example 4=
 
|x4= Compare (each command was executed 100000 times to gather statistics):<code>[[floor]] [[random]] 10;
// 0 - 10099 (10%)
// 1 - 10040 (10%)
// 2 - 10154 (10%)
// 3 - 9910 (10%)
// 4 - 10023 (10%)
// 5 - 9937 (10%)
// 6 - 10118 (10%)
// 7 - 9716 (10%)
// 8 - 9986 (10%)
// 9 - 10017 (10%)
 
[[floor]] [[random]] [0,5,10];
// 0 - 109 (0%)
// 1 - 1604 (2%)
// 2 - 6839 (7%)
// 3 - 16671 (17%)
// 4 - 24706 (25%)
// 5 - 24702 (25%)
// 6 - 16626 (17%)
// 7 - 6925 (7%)
// 8 - 1702 (2%)
// 9 - 116 (0%)
 
[[floor]] [[random]] [0,10,0];
// 0 - 19 (0%)
// 1 - 209 (0%)
// 2 - 817 (1%)
// 3 - 2384 (2%)
// 4 - 4841 (5%)
// 5 - 8976 (9%)
// 6 - 14067 (14%)
// 7 - 18955 (19%)
// 8 - 23605 (24%)
// 9 - 26127 (26%)
 
[[floor]] [[random]] [0,10,5];
// 0 - 11 (0%)
// 1 - 98 (0%)
// 2 - 430 (0%)
// 3 - 1149 (1%)
// 4 - 2384 (2%)
// 5 - 4546 (5%)
// 6 - 8612 (9%)
// 7 - 16283 (16%)
// 8 - 28393 (28%)
// 9 - 38094 (38%)</code>  |= Example 2
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| [[Math Commands]], [[selectRandom]], [[selectRandomWeighted]] |= See also
| [[Math Commands]], [[selectRandom]], [[selectRandomWeighted]] |See also=
 
}}
}}


<h3 style="display:none">Notes</h3>
<h3 style="display:none">Notes</h3>


[[Category:Scripting Commands|RANDOM]]
[[Category:Scripting Commands|{{uc:{{PAGENAME}}}}]]
[[Category:Scripting Commands OFP 1.46|{{uc:{{PAGENAME}}}}]]
[[Category:Scripting Commands OFP 1.96|{{uc:{{PAGENAME}}}}]]
[[Category:Scripting Commands OFP 1.99|{{uc:{{PAGENAME}}}}]]
[[Category:Scripting Commands OFP 1.99|{{uc:{{PAGENAME}}}}]]
[[Category:Scripting Commands OFP 1.96|RANDOM]]
[[Category:Scripting Commands ArmA|{{uc:{{PAGENAME}}}}]]
[[Category:Scripting Commands OFP 1.46|RANDOM]]
[[Category:Scripting Commands ArmA|RANDOM]]
[[Category:Command_Group:_Variables|{{uc:{{PAGENAME}}}}]]
[[Category:Command_Group:_Variables|{{uc:{{PAGENAME}}}}]]
[[Category:Scripting Commands ArmA2|{{uc:{{PAGENAME}}}}]]
[[Category:Scripting Commands ArmA2|{{uc:{{PAGENAME}}}}]]
[[Category:Scripting_Commands_Take_On_Helicopters|{{uc:{{PAGENAME}}}}]]
[[Category:Scripting Commands Arma 3|{{uc:{{PAGENAME}}}}]]
[[Category:Scripting Commands Arma 3|{{uc:{{PAGENAME}}}}]]
[[Category:Scripting_Commands_Take_On_Helicopters|{{uc:{{PAGENAME}}}}]]


<!-- CONTINUE Notes -->
<!-- CONTINUE Notes -->
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<code>_Xrnd = round(random 200) -100;</code>
<code>_Xrnd = round(random 200) -100;</code>
This will yield numbers between -100 and 100.
This will yield numbers between -100 and 100.
* Be careful using random numbers in multiplayer, each client will come up with a different result. See multiplayer tutorials for more general information about locality.  
* Be careful using random numbers in multiplayer, each client will come up with a different result. See multiplayer tutorials for more general information about locality.  
* The number returned is unlikely to be a whole number.<br>To return a whole number use either '''[[round]]''', '''[[ceil]]''' or '''[[floor]]''' together with '''random''':<br>
* The number returned is unlikely to be a whole number.<br />
x=round(random 5) will return 0,1,2,3,4 or 5. (non-uniform distribution, 0 and 5 are half as likely to be selected than any of the other numbers)
To return a whole number use either '''[[round]]''', '''[[ceil]]''' or '''[[floor]]''' together with [[random]]:
<br>x=floor(random 5) will return 0,1,2,3 or 4.  (uniform distribution, all numbers have the same probability of being selected)
<code>x = round(random 5) will return 0,1,2,3,4 or 5. (non-uniform distribution, 0 and 5 are half as likely to be selected than any of the other numbers)
<br>x=ceil(random 5) will return  0,1,2,3,4 or 5. (0 is very unlikely, but possible, as ceil 0 is 0)
x = floor(random 5) will return 0,1,2,3 or 4.  (uniform distribution, all numbers have the same probability of being selected)
x = ceil(random 5) will return  0,1,2,3,4 or 5. (0 is very unlikely, but possible, as ceil 0 is 0)</code>
</dd>
<dd class="notedate">Posted on July 22, 2018 - 12:58 (UTC+2)</dd>
<dt class="note">[[User:Lou Montana|Lou Montana]]</dt>
<dd class="note">
{{{!}}class="bikitable"
{{!}}+ Repartition comparison
! Formula
! 0
! 1
! 2
! 3
! 4
! 5
! 6
! 7
! 8
! 9
{{!}}-
{{!}} [[floor]] [[random]] 10;
{{!}} 10%
{{!}} 10%
{{!}} 10%
{{!}} 10%
{{!}} 10%
{{!}} 10%
{{!}} 10%
{{!}} 10%
{{!}} 10%
{{!}} 10%
{{!}}-
{{!}} [[floor]] [[random]] [0, 5, 10]
{{!}} 0%
{{!}} 2%
{{!}} 7%
{{!}} 17%
{{!}} 25%
{{!}} 25%
{{!}} 17%
{{!}} 7%
{{!}} 2%
{{!}} 0%
{{!}}-
{{!}} [[floor]] [[random]] [0, 10, 0]
{{!}} 0%
{{!}} 0%
{{!}} 1%
{{!}} 2%
{{!}} 5%
{{!}} 9%
{{!}} 14%
{{!}} 19%
{{!}} 24%
{{!}} 26%
{{!}}-
{{!}} [[floor]] [[random]] [0, 10, 5]
{{!}} 0%
{{!}} 0%
{{!}} 0%
{{!}} 1%
{{!}} 2%
{{!}} 5%
{{!}} 9%
{{!}} 16%
{{!}} 28%
{{!}} 38%
{{!}}}
</dd>
</dd>
</dl>
</dl>
<!-- DISCONTINUE Notes -->
<!-- DISCONTINUE Notes -->

Revision as of 11:58, 22 July 2018

Logo A0.png1.00
Hover & click on the images for description

Description

Description:
bellcurve.jpg
Random real (floating point) value from 0 (inclusive) to x (not inclusive).


Since Arma 3 v1.55.133393 alternative syntax is added, allowing to define Gaussian Distribution params. Uses the same method as setTriggerTimeout command. Quite useful for spawning loot for example, making more valuable items more rare (Alternative Syntax 1)

Since Arma 3 v1.67.139663 two alternative syntaxes are available:

  • allowing to generate semi-random number based on provided seed (Alternative Syntax 2)
  • generating pseudo-random noise texture based on provided seed and returning a single number between 0 (included) and 1 (excluded) at supplied x and y coordinates (Alternative Syntax 3)
Groups:
Uncategorised

Syntax 1

Syntax:
random x
Parameters:
x: Number
Return Value:
Number

Syntax 2

Syntax:
random [min, mid, max]        (Since Arma 3 v1.55.133393)
Parameters:
[min, mid, max]: Array
min: Number
mid: Number
max: Number
Return Value:
Number

Syntax 3

Syntax:
seed random x        (Since Arma 3 v1.67.139663)
Parameters:
seed: Number
x: Number
Return Value:
Number

Syntax 4

Syntax:
seed random [x, y]        (Since Arma 3 v1.67.139663)
Parameters:
seed: Number
[x, y]: Array position on the Perlin noise texture
x: Number
y: Number
Return Value:
Number

Examples

Example 1:
_rNumber = random 1;
Example 2:
_rNumber = random -10;
Example 3:
Generate random position inside a circle _center getPos [_radius * sqrt random 1, random 360];
Example 4:
To select random value from an array: _array = ["apples", "pears", "bananas", "M16"]; _random = _array select floor random count _array; // since Arma 3 v1.55.133393 _random = selectRandom _array;

Additional Information

See also:
Math CommandsselectRandomselectRandomWeighted

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

Notes

Posted on July 12, 2015 - 20:32 (UTC)
Hcpookie
Random selections including negative numbers can be obtained via: _Xrnd = round(random 200) -100; This will yield numbers between -100 and 100.
  • Be careful using random numbers in multiplayer, each client will come up with a different result. See multiplayer tutorials for more general information about locality.
  • The number returned is unlikely to be a whole number.
To return a whole number use either round, ceil or floor together with random: x = round(random 5) will return 0,1,2,3,4 or 5. (non-uniform distribution, 0 and 5 are half as likely to be selected than any of the other numbers) x = floor(random 5) will return 0,1,2,3 or 4. (uniform distribution, all numbers have the same probability of being selected) x = ceil(random 5) will return 0,1,2,3,4 or 5. (0 is very unlikely, but possible, as ceil 0 is 0)
Posted on July 22, 2018 - 12:58 (UTC+2)
Lou Montana
Repartition comparison
Formula 0 1 2 3 4 5 6 7 8 9
floor random 10; 10% 10% 10% 10% 10% 10% 10% 10% 10% 10%
floor random [0, 5, 10] 0% 2% 7% 17% 25% 25% 17% 7% 2% 0%
floor random [0, 10, 0] 0% 0% 1% 2% 5% 9% 14% 19% 24% 26%
floor random [0, 10, 5] 0% 0% 0% 1% 2% 5% 9% 16% 28% 38%
Retrieved from "https://community.bistudio.com/wiki?title=random&oldid=108908"