Difference between revisions of "random"
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Lou Montana (talk  contribs) (Add syntax #3 details) 
bovine3dom (talk  contribs) m (Added link to correct distribution for people who would be very confused at the concept of a minimum and maximum for a normal distribution.) 

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[[Image:bellcurve.jpgright200px]] Random real (floating point) value from 0 (inclusive) to x (not inclusive).<br />  [[Image:bellcurve.jpgright200px]] Random real (floating point) value from 0 (inclusive) to x (not inclusive).<br />  
<br />  <br />  
−  Since Arma 3 v1.55.133393 alternative syntax is added, allowing  +  Since Arma 3 v1.55.133393 alternative syntax is added, allowing the definition of [https://en.wikipedia.org/wiki/Normal_distribution Gaussian Distribution]<ref>Technically, it is a rescaled [https://en.wikipedia.org/wiki/Irwin–Hall_distribution IrwinHall Distribution] with n = 4.</ref> 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 two alternative syntaxes are available:  Since Arma 3 v1.67.139663 two alternative syntaxes are available:  
* allowing to generate semirandom number based on provided seed ('''Alternative Syntax 2''')  * allowing to generate semirandom number based on provided seed ('''Alternative Syntax 2''') 
Revision as of 14:05, 8 March 2019
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Description
 Description:

Random real (floating point) value from 0 (inclusive) to x (not inclusive).
Since Arma 3 v1.55.133393 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)
Since Arma 3 v1.67.139663 two alternative syntaxes are available: allowing to generate semirandom number based on provided seed (Alternative Syntax 2)
 generating pseudorandom 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)
Syntax
Alternative Syntax
 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
Alternative Syntax 2
 Syntax:
 seed random x (Since Arma 3 v1.67.139663)
 Parameters:
 seed: Number
 x: Number
 Return Value:
 Number
Alternative Syntax 3
 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
Notes
Only post proven facts here. Report bugs on the feedback tracker. Use the Talk page or the Forums for discussions.
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.
x = round(random 5) will return 0,1,2,3,4 or 5. (nonuniform 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 IrwinHall Distribution with n = 4.
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