correlation.js

// Correlation Test
const data = require("./data3.js");
const a = "events";
const b = "squirrel";
//const data = [
//  {x: 3, y: true},
//  {x: 10, y: true},
//  {x: 12, y: false},
//  {x: 4, y: false},
//  {x: 7, y: false},
//
//]
//const data = [
//  {a: 215, b: 14.2},
//  {a: 325, b: 16.4},
//  {a: 185, b: 11.9},
//  {a: 332, b: 15.2},
//  {a: 406, b: 18.5},
//  {a: 522, b: 22.1},
//  {a: 412, b: 19.4},
//  {a: 614, b: 25.1},
//  {a: 544, b: 23.4},
//  {a: 421, b: 18.1},
//  {a: 445, b: 22.6},
//  {a: 408, b: 17.2},
//]

//For numbers
const getMean = (d, key, N) => {
  let sum = d.reduce((acc, cur) => ({ [key]: acc[key] + cur[key] }))[key];
  return sum / N;
};

const getABComb = (d, keyA, keyB, meanA, meanB) => {
  return d
    .map(el => (el[keyA] - meanA) * (el[keyB] - meanB))
    .reduce((acc, cur) => acc + cur);
};

const getDeviationScores = (d, key, mean, N) => {
  const pow2Arr = d.map(el => (el[key] - mean) * (el[key] - mean));
  const variance = pow2Arr.reduce((acc, cur) => acc + cur);
  return Math.round(variance * 1000) / 1000;
};

const getN = d => Object.keys(d).length;

const getR = (ABComb, devA, devB) => ABComb / Math.sqrt(devA * devB);

//For Binary Correlation
const getBinR = t => {
  console.log("a: ", t[3] * t[0] - t[2] * t[1]);
  console.log(
    "b: ",
    Math.sqrt((t[2] + t[3]) * (t[0] + t[1]) * (t[1] * t[3]) * (t[0] + t[2]))
  );
  return (
    (t[3] * t[0] - t[2] * t[1]) /
    Math.sqrt((t[2] + t[3]) * (t[0] + t[1]) * (t[1] * t[3]) * (t[0] + t[2]))
  );
};

const buildTable = (arg, d, keyA, keyB) => {
  let t = [0, 0, 0, 0];
  for (let i in d) {
    const obj = d[i];
    let index = 0;
    if (d[i][keyA].indexOf(arg) != -1) index++;
    if (d[i][keyB]) index += 2;
    t[index]++;
  }
  return t;
};

const getKeyVals = (d, key) => {
  const aKeys = [];
  for (let i in d) {
    for (let j in d[i][key]) {
      if (aKeys.indexOf(d[i][key][j]) == -1) aKeys.push(d[i][key][j]);
    }
  }
  return aKeys;
};

const keyVals = getKeyVals(data, a);

const getCorrelations = (keyVals, action) => {
  let arr = [];
  for (let i in keyVals) {
    arr.push({
      name: keyVals[i],
      phi: action(buildTable(keyVals[i], data, a, b))
    });
  }
  return arr;
};

console.log(getCorrelations(getKeyVals(data, a), getBinR));

const N = getN(data);
const meanA = getMean(data, a, N);
const meanB = getMean(data, b, N);
const devA = getDeviationScores(data, a, meanA, N);
const devB = getDeviationScores(data, b, meanB, N);
const ABComb = getABComb(data, a, b, meanA, meanB);
const r = getR(ABComb, devA, devB);

console.log("abComb: ", ABComb);
console.log("N: ", N);
console.log("devA: ", devA);
console.log("devB: ", devB);
console.log("meanA: ", meanA);
console.log("meanB: ", meanB);
console.log("r: ", r);