fake age range numbers via gaussian distribution

fake-age-bins.js

var gaussian = require('gaussian');

// mean is the center of the distritubion
var mean = 34.5;
var variance = 300;

var distribution = gaussian(mean, variance);

// number of samples
var x = 1000;

var results = [];

// bins
var bins = ([{
  start: 16,
  stop: 18
}, {
  start: 18,
  stop: 25
}, {
  start: 25,
  stop: 35
}, {
  start: 35,
  stop: 45
}, {
  start: 45,
  stop: 55
}, {
  start: 55,
  stop: 65
}, {
  start: 65,
  stop: 99
}]).map(bin => {
  bin.results = [];
  return bin;
});

// take a sample
for (let i = 0; i <= x; i++) {
  results.push(distribution.ppf(Math.random()));
}

// sort samples to make bin-ing faster
results = results.sort((a,b) => a > b ? 1 : -1);

// put results in bins
var bindex = 0;
var bin = bins[0];
results.forEach(function(result) {
  if (result < 0) return;
  // find the appropriate bin
  while (result > bin.stop && bindex <= bins.length) {
    bindex++;
    bin = bins[bindex];
  }
  if (result < bin.start) return;
  bin.results.push(result);
});


bins.forEach((bin, i) => {
  var int = ~~(bin.results.length / 10);
  console.log(bin.start, bin.stop, new Array(int).fill('x').join(''));
});

/* 
example results

16 18 'xx'
18 25 'xxxxxxxxxxx'
25 35 'xxxxxxxxxxxxxxxxxxxxxxx'
35 45 'xxxxxxxxxxxxxxxxxxxxx'
45 55 'xxxxxxxxxxxxxxx'
55 65 'xxxxxxx'
65 99 'xxx'
*/

package.json

{
  "name": "fake-age-bins",
  "version": "1.0.0",
  "description": "",
  "main": "fake-age-bins.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "gaussian": "^1.1.0"
  }
}