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{{ | {{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= 1.50 | |||
|game6= tkoh | |||
|version6= 1.00 | |||
|game7= arma3 | |||
|version7= 0.50 | |||
|gr1= Math | |||
|descr= [[Image:bellcurve.jpg|right|200px]] Random real (floating point) value from 0 (inclusive) to x (not inclusive).<br><br> | |||
{{GVI|arma3|1.56}} alternative syntax is added, allowing the definition of {{Wikipedia|Normal_distribution|Gaussian Distribution}}<ref>Technically, it is a rescaled {{Wikipedia|Bates_distribution|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.</ref> params. Uses the same method as [[setTriggerTimeout]] command. Quite useful for spawning loot for example, making more valuable items more rare ({{HashLink|#Alternative Syntax 1}})<br><br> | |||
{{GVI|arma3|1.68}} two alternative syntaxes are available: | |||
* allowing to generate {{Wikipedia|Random seed|seed-based}} random number based on provided seed ({{HashLink|#Alternative Syntax 2}}) | |||
* generating {{Wikipedia|Random seed|seed-based}} random noise texture based on provided seed and returning a single number between 0 (included) and 1 (excluded) at supplied ''x'' and ''y'' coordinates ({{HashLink|#Alternative Syntax 3}}) | |||
|s1= [[random]] x | |||
|p1= x: [[Number]] | |p1= x: [[Number]] | ||
|s2= | |r1= [[Number]] | ||
|p21= [min, mid, max]: [[Array]] | |||
|p22= min: [[Number]] | |s2= [[random]] [min, mid, max] {{Since|arma3|1.56|y}} | ||
|p23= mid: [[Number]] | |||
|p21= [min, mid, max]: [[Array]] | |||
|p22= min: [[Number]] | |||
|p23= mid: [[Number]] | |||
| | |p24= max: [[Number]] | ||
| | |r2= [[Number]] | ||
|s3= seed [[random]] x {{Since|arma3|1.68|y}} | |||
| | |||
| | |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]] | ||
| | |r3= [[Number]] - Value from 0 to x | ||
|s4= seed [[random]] [x, y] {{Since|arma3|1.68|y}} | |||
|p61= seed: [[Number]] | |||
|p62= [x, y]: [[Array]] - texture position (''not'' a Perlin noise) | |||
| | |p63= x: [[Number]] | ||
[[ | |p64= y: [[Number]] | ||
[[ | |r4= [[Number]] - Value from 0 to 1 | ||
|x1= <code>_rNumber = [[random]] 1;</code> | |||
| [[ | |x2= <code>_rNumber = [[random]] -10;</code> | ||
|x3= Generate a random position inside a circle (see also [[Example Code: Random Area Distribution]]) | |||
<code>_center [[getPos]] [_radius * [[sqrt]] [[random]] 1, [[random]] 360];</code> | |||
< | |x4= To select random value from an array: | ||
<code>_array = ["apples", "pears", "bananas", "M16"]; | |||
_random = _array [[select]] [[floor]] [[random]] [[count]] _array; | |||
{{cc|{{Since|arma3|1.56}}}} | |||
_random = [[selectRandom]] _array;</code> | |||
|seealso= [[selectRandom]], [[selectRandomWeighted]] | |||
[[ | }} | ||
[[ | |||
<dl class="command_description"> | <dl class="command_description"> | ||
<dt></dt> | |||
<dd class="notedate">Posted on July 12, 2015 - 20:32 (UTC)</dd> | <dd class="notedate">Posted on July 12, 2015 - 20:32 (UTC)</dd> | ||
<dt class="note">[[User:Hcpookie|Hcpookie]]</dt> | <dt class="note">[[User:Hcpookie|Hcpookie]]</dt> | ||
<dd class="note"> | <dd class="note"> | ||
Random selections including negative numbers can be obtained via: | Random selections including negative numbers can be obtained via: | ||
<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. | |||
* 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]]: | |||
<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) | |||
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="wikitable" | |||
|+ 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> | ||
Revision as of 18:54, 17 July 2021
Description
- Description:
- Random real (floating point) value from 0 (inclusive) to x (not inclusive).
1.56 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)
1.68 two alternative syntaxes are available:
- allowing to generate seed-based random number based on provided seed (Alternative Syntax 2)
- generating seed-based 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:
- Math
Syntax 1
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.
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%
- ↑ 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.
Categories:
- Scripting Commands
- Introduced with Operation Flashpoint version 1.00
- Operation Flashpoint: New Scripting Commands
- Operation Flashpoint: Scripting Commands
- Operation Flashpoint: Elite: Scripting Commands
- ArmA: Armed Assault: Scripting Commands
- Arma 2: Scripting Commands
- Arma 2: Operation Arrowhead: Scripting Commands
- Take On Helicopters: Scripting Commands
- Arma 3: Scripting Commands
- Command Group: Math