@ruananqing/unequal-probability-random v1.0.4

Introduction:

unequal_probability_random is a CommomJs style JavaScript package for returning unequal probability numbers or strings.

Installation:

npm install @ruananqing/unequal-probability-random

Usage for Node.js:

1.For returning unequal random strings:

const UPR = require('@ruananqing/unequal-probability-random');

// when options like this,  you will get the random string(options' keys) with unequal probability
// note: the summation(total probability) of the options' values(probabilitys) should be a 1 when each value added
let options = {
    'a': 0.1,
    'b': 0.2,
    'c': 0.3,
    'd': 0.4
};
const uprandom = UPR.randomStringFunction(options);
uprandom(); //return 'a' or 'b' or 'c' or 'd' with unequal probability 10%, 20%, 30%, 40%

Test for upradom()'s strings:

let times = 100000; //a bigger times means closer probabilities
let Atimes = 0;
let Btimes = 0;
let Ctimes = 0;
let Dtimes = 0;

for (let i = 0; i < times; i++) {
    let random = uprandom();
    if (random == 'a') {
        Atimes++;
    } else if (random == 'b') {
        Btimes++;
    } else if (random == 'c') {
        Ctimes++;
    } else if (random == 'd') {
        Dtimes++;
    }
}

console.log({
    'a': Atimes/times,
    'b': Btimes/times,
    'c': Ctimes/times,
    'd': Dtimes/times
});

/**
 * { a: 0.09985, 
 *   b: 0.20015, 
 *   c: 0.29824, 
 *   d: 0.40176 }
 * *

2.For returning unequal random numbers in different areas:

const UPR = require('@ruananqing/unequal-probability-random');

// when options like this,  you will get the random float number(numbers in options' keys' area: 20-9999) with unequal probability
// note: the summation(total probability) of the options' values(probabilitys) should be a 1 when each value added
let options = {
    '20-30': 0.05,
    '30-60': 0.3,
    '60-80': 0.22,
    '80-85': 0.08,
    '85-9999': 0.35
}
const uprandom = UPR.randomNumberFunction(options);
uprandom(); //return a float number(in 20-9999) with unequal probability in different area

Test for upradom()'s numbers:

let times = 100000; //a bigger times means closer probabilities
let Area1times = 0;
let Area2times = 0;
let Area3times = 0;
let Area4times = 0;
let Area5times = 0;

for (let i = 0; i < times; i++) {
    let random = uprandom();
    if (random >= 20 && random < 30) {
        Area1times++;
    } else if (random >= 30 && random < 60) {
        Area2times++;
    } else if (random >= 60 && random < 80) {
        Area3times++;
    } else if (random >= 80 && random < 85) {
        Area4times++;
    } else {
        Area5times++;
    }
}

console.log({
    '20-30': Area1times/times, 
    '30-60': Area2times/times,
    '60-80': Area3times/times,
    '80-85': Area4times/times,
    '85-9999': Area5times/times
});

/**
 * { '20-30': 0.0499,
 * '30-60': 0.29853,
 * '60-80': 0.22078,
 * '80-85': 0.07997,
 * '85-9999': 0.35082 }
*/