JavaScript Non-Linear Random Numbers

Posted at

statistics-and-probability-560x560

While normall dice toss will give you 1partn where n is the number of sides-of the dice.

this is an equal chance of each of the sides to come in 1 toss.

there are few easy ways of modifying a toss-result, using some of JavaScript's native Math functions, such as modulus (%) and power (Math.pow), there are, naturally other that will work just as well, essentially once should choose a set of functions that will increase or modify the numeric value in a non-linear 'way', Math.pow is a good example since it may work exponentially, combined with modulus operation to keep the value 'in-range' we can play with JavaScript's pseudo-random implementation to make some *cool variations of good old dice-toss..

*:cool? well.. if you're a math-geek like me.. :)






let us get some nice code going, the following uses:


next I (as.. this code) runs few virtual-dice-toss and collecting the result,
collecting some statistic by comparing it with the average expected by linear dice-toss.



var arr = [];
var r = function(max){
return Math.abs(~~(Math.random()*max));
};
var r_modulu_half = function(max){
return Math.abs(r(max) % (max/2));
};
var r_modulu_unknownrandom = function(max){
return Math.abs(r(max) % r(max));
};
var r_modulu_unknownrandom_modulu_unknownrandom = function(max){
return Math.abs(r(max) % r(r(max)));
};
var r_pow_e_modulu_max = function(max){
return Math.abs(~~(Math.pow(r(max),Math.E))) % max;
};
var r_pow_r_modulu_max = function(max){
return Math.abs(~~(Math.pow(Math.E,r(max)))) % max;
};



var a;
var max = 30;
var roll = 999999;
var avg = ~~(roll / max);
var arr_statistics = [];

//fill
for(var i=0; i //a = r(max); //linear.
//a = r_modulu_half(max); //module half of max value
//a = r_modulu_unknownrandom(max); //modulu of unknown random
//a = r_modulu_unknownrandom_modulu_unknownrandom(max); //continues 2 random operations.
//a = r_pow_e_modulu_max(max);
a = r_modulu_unknownrandom(r_pow_r_modulu_max(max));
arr[a] = (arr[a] || 0) + 1;
}

//statistics jumps
for(var i=0; i arr_statistics[i] = ((arr[i]||0)/avg)*100;
arr_statistics[i] = arr_statistics[i].toFixed(2) + "%";
}

console.log("rendered result",arr, "diff from expected avg",arr_statistics);


the above code variation uses the JavaScript pseudo-random in a variation that renders a result that 'favored' the first cells.

rand