Difference between revisions of "random"

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m (Text replacement - " |game5= arma2oa |version5= 1.51 " to " |game5= arma2oa |version5= 1.50 ")
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|s3= seed [[random]] x {{Since|arma3|1.68|y}}
 
|s3= seed [[random]] x {{Since|arma3|1.68|y}}
  
|p41= seed: [[Number]]
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|p41= seed: [[Number]] - an '''integer'''. Any float value will be truncated (e.g -0.9, -0.1, 0.1 or 0.9 will be read as '''0''')
  
 
|p42= x: [[Number]]
 
|p42= x: [[Number]]
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|x3= Generate a random position inside a circle (see also [[Example Code: Random Area Distribution]])
 
|x3= Generate a random position inside a circle (see also [[Example Code: Random Area Distribution]])
<code>_center [[getPos]] [<nowiki/>_radius * [[sqrt]] [[random]] 1, [[random]] 360];</code>
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<code>_center [[getPos]] [_radius * [[sqrt]] [[random]] 1, [[random]] 360];</code>
  
 
|x4= To select random value from an array:
 
|x4= To select random value from an array:
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* The number returned is unlikely to be a whole number.<br>
 
* 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]]:
 
To return a whole number use either '''[[round]]''', '''[[ceil]]''' or '''[[floor]]''' together with [[random]]:
<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)
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<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)
x = floor(random 5) will return 0,1,2,3 or 4.  (uniform distribution, all numbers have the same probability of being selected)
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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>
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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>
  
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|}
 
|}
 
</dd>
 
</dd>
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</dl>
 
</dl>

Revision as of 19:54, 17 July 2021

Hover & click on the images for description

Description

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

Arma 3 logo black.png1.56 alternative syntax is added, allowing the definition of Gaussian Distribution[1] params. Uses the same method as setTriggerTimeout command. Quite useful for spawning loot for example, making more valuable items more rare (Alternative Syntax 1)

Arma 3 logo black.png1.68 two alternative syntaxes are available:

Groups:
Math

Syntax 1

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

Syntax 2

Syntax:
random [min, mid, max] Template:Since
Parameters:
[min, mid, max]: Array
min: Number
mid: Number
max: Number
Return Value:
Number

Syntax 3

Syntax:
seed random x Template:Since
Parameters:
seed: Number - an integer. Any float value will be truncated (e.g -0.9, -0.1, 0.1 or 0.9 will be read as 0)
x: Number
Return Value:
Number - Value from 0 to x

Syntax 4

Syntax:
seed random [x, y] Template:Since
Parameters:
seed: Number
[x, y]: Array - texture position (not a Perlin noise)
x: Number
y: Number
Return Value:
Number - Value from 0 to 1

Examples

Example 1:
_rNumber = random 1;
Example 2:
_rNumber = random -10;
Example 3:
Generate a random position inside a circle (see also Example Code: Random Area Distribution) _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; // Template:Since _random = selectRandom _array;

Additional Information

See also:
selectRandomselectRandomWeighted

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 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%
  1. Technically, it is a rescaled Bates distribution with n = 4. The distribution is split in two at its midpoint and scaled linearly such that its maximum lies at the specified midpoint.