startit/eloquentjavascript/data_structures.js

// Weresquirrel

var JOURNAL = [
  { "events": ["carrot", "exercise", "weekend"], "squirrel": false },
  { "events": ["bread", "pudding", "brushed teeth", "weekend", "touched tree"], "squirrel": false },
  { "events": ["carrot", "nachos", "brushed teeth", "cycling", "weekend"], "squirrel": false },
  { "events": ["brussel sprouts", "ice cream", "brushed teeth", "computer", "weekend"], "squirrel": false },
  { "events": ["potatoes", "candy", "brushed teeth", "exercise", "weekend", "dentist"], "squirrel": false },
  { "events": ["brussel sprouts", "pudding", "brushed teeth", "running", "weekend"], "squirrel": false },
  { "events": ["pizza", "brushed teeth", "computer", "work", "touched tree"], "squirrel": false },
  { "events": ["bread", "beer", "brushed teeth", "cycling", "work"], "squirrel": false },
  { "events": ["cauliflower", "brushed teeth", "work"], "squirrel": false },
  { "events": ["pizza", "brushed teeth", "cycling", "work"], "squirrel": false },
  { "events": ["lasagna", "nachos", "brushed teeth", "work"], "squirrel": false },
  { "events": ["brushed teeth", "weekend", "touched tree"], "squirrel": false },
  { "events": ["lettuce", "brushed teeth", "television", "weekend"], "squirrel": false },
  { "events": ["spaghetti", "brushed teeth", "work"], "squirrel": false },
  { "events": ["brushed teeth", "computer", "work"], "squirrel": false },
  { "events": ["lettuce", "nachos", "brushed teeth", "work"], "squirrel": false },
  { "events": ["carrot", "brushed teeth", "running", "work"], "squirrel": false },
  { "events": ["brushed teeth", "work"], "squirrel": false },
  { "events": ["cauliflower", "reading", "weekend"], "squirrel": false },
  { "events": ["bread", "brushed teeth", "weekend"], "squirrel": false },
  { "events": ["lasagna", "brushed teeth", "exercise", "work"], "squirrel": false },
  { "events": ["spaghetti", "brushed teeth", "reading", "work"], "squirrel": false },
  { "events": ["carrot", "ice cream", "brushed teeth", "television", "work"], "squirrel": false },
  { "events": ["spaghetti", "nachos", "work"], "squirrel": false },
  { "events": ["cauliflower", "ice cream", "brushed teeth", "cycling", "work"], "squirrel": false },
  { "events": ["spaghetti", "peanuts", "computer", "weekend"], "squirrel": true },
  { "events": ["potatoes", "ice cream", "brushed teeth", "computer", "weekend"], "squirrel": false },
  { "events": ["potatoes", "ice cream", "brushed teeth", "work"], "squirrel": false },
  { "events": ["peanuts", "brushed teeth", "running", "work"], "squirrel": false },
  { "events": ["potatoes", "exercise", "work"], "squirrel": false },
  { "events": ["pizza", "ice cream", "computer", "work"], "squirrel": false },
  { "events": ["lasagna", "ice cream", "work"], "squirrel": false },
  { "events": ["cauliflower", "candy", "reading", "weekend"], "squirrel": false },
  { "events": ["lasagna", "nachos", "brushed teeth", "running", "weekend"], "squirrel": false },
  { "events": ["potatoes", "brushed teeth", "work"], "squirrel": false },
  { "events": ["carrot", "work"], "squirrel": false },
  { "events": ["pizza", "beer", "work", "dentist"], "squirrel": false },
  { "events": ["lasagna", "pudding", "cycling", "work"], "squirrel": false },
  { "events": ["spaghetti", "brushed teeth", "reading", "work"], "squirrel": false },
  { "events": ["spaghetti", "pudding", "television", "weekend"], "squirrel": false },
  { "events": ["bread", "brushed teeth", "exercise", "weekend"], "squirrel": false },
  { "events": ["lasagna", "peanuts", "work"], "squirrel": true },
  { "events": ["pizza", "work"], "squirrel": false },
  { "events": ["potatoes", "exercise", "work"], "squirrel": false },
  { "events": ["brushed teeth", "exercise", "work"], "squirrel": false },
  { "events": ["spaghetti", "brushed teeth", "television", "work"], "squirrel": false },
  { "events": ["pizza", "cycling", "weekend"], "squirrel": false },
  { "events": ["carrot", "brushed teeth", "weekend"], "squirrel": false },
  { "events": ["carrot", "beer", "brushed teeth", "work"], "squirrel": false },
  { "events": ["pizza", "peanuts", "candy", "work"], "squirrel": true },
  { "events": ["carrot", "peanuts", "brushed teeth", "reading", "work"], "squirrel": false },
  { "events": ["potatoes", "peanuts", "brushed teeth", "work"], "squirrel": false },
  { "events": ["carrot", "nachos", "brushed teeth", "exercise", "work"], "squirrel": false },
  { "events": ["pizza", "peanuts", "brushed teeth", "television", "weekend"], "squirrel": false },
  { "events": ["lasagna", "brushed teeth", "cycling", "weekend"], "squirrel": false },
  { "events": ["cauliflower", "peanuts", "brushed teeth", "computer", "work", "touched tree"], "squirrel": false },
  { "events": ["lettuce", "brushed teeth", "television", "work"], "squirrel": false },
  { "events": ["potatoes", "brushed teeth", "computer", "work"], "squirrel": false },
  { "events": ["bread", "candy", "work"], "squirrel": false },
  { "events": ["potatoes", "nachos", "work"], "squirrel": false },
  { "events": ["carrot", "pudding", "brushed teeth", "weekend"], "squirrel": false },
  { "events": ["carrot", "brushed teeth", "exercise", "weekend", "touched tree"], "squirrel": false },
  { "events": ["brussel sprouts", "running", "work"], "squirrel": false },
  { "events": ["brushed teeth", "work"], "squirrel": false },
  { "events": ["lettuce", "brushed teeth", "running", "work"], "squirrel": false },
  { "events": ["candy", "brushed teeth", "work"], "squirrel": false },
  { "events": ["brussel sprouts", "brushed teeth", "computer", "work"], "squirrel": false },
  { "events": ["bread", "brushed teeth", "weekend"], "squirrel": false },
  { "events": ["cauliflower", "brushed teeth", "weekend"], "squirrel": false },
  { "events": ["spaghetti", "candy", "television", "work", "touched tree"], "squirrel": false },
  { "events": ["carrot", "pudding", "brushed teeth", "work"], "squirrel": false },
  { "events": ["lettuce", "brushed teeth", "work"], "squirrel": false },
  { "events": ["carrot", "ice cream", "brushed teeth", "cycling", "work"], "squirrel": false },
  { "events": ["pizza", "brushed teeth", "work"], "squirrel": false },
  { "events": ["spaghetti", "peanuts", "exercise", "weekend"], "squirrel": true },
  { "events": ["bread", "beer", "computer", "weekend", "touched tree"], "squirrel": false },
  { "events": ["brushed teeth", "running", "work"], "squirrel": false },
  { "events": ["lettuce", "peanuts", "brushed teeth", "work", "touched tree"], "squirrel": false },
  { "events": ["lasagna", "brushed teeth", "television", "work"], "squirrel": false },
  { "events": ["cauliflower", "brushed teeth", "running", "work"], "squirrel": false },
  { "events": ["carrot", "brushed teeth", "running", "work"], "squirrel": false },
  { "events": ["carrot", "reading", "weekend"], "squirrel": false },
  { "events": ["carrot", "peanuts", "reading", "weekend"], "squirrel": true },
  { "events": ["potatoes", "brushed teeth", "running", "work"], "squirrel": false },
  { "events": ["lasagna", "ice cream", "work", "touched tree"], "squirrel": false },
  { "events": ["cauliflower", "peanuts", "brushed teeth", "cycling", "work"], "squirrel": false },
  { "events": ["pizza", "brushed teeth", "running", "work"], "squirrel": false },
  { "events": ["lettuce", "brushed teeth", "work"], "squirrel": false },
  { "events": ["bread", "brushed teeth", "television", "weekend"], "squirrel": false },
  { "events": ["cauliflower", "peanuts", "brushed teeth", "weekend"], "squirrel": false }
];

function tableFor(event, journal) {
  let table = [0, 0, 0, 0];
  for (let i = 0; i < journal.length; i++) {
    let entry = journal[i], index = 0;
    if (entry.events.includes(event)) index += 1;
    if (entry.squirrel) index += 2;
    table[index] += 1;
  }
  return table;
}
console.log(tableFor("pizza", JOURNAL));


function phi(table) {
  return (table[3] * table[0] - table[2] * table[1]) / Math.sqrt(
    (table[2] + table[3]) *
    (table[0] + table[1]) *
    (table[1] + table[3]) *
    (table[0] + table[2]));
};
function journalEvents(journal) {
  let events = [];
  for (let entry of journal) {
    for (let event of entry.events) {
      if (!events.includes(event)) {
        events.push(event);
      }
    }
  }
  return events;
}
console.log(journalEvents(JOURNAL));

for (let event of journalEvents(JOURNAL)) {
  let correlation = phi(tableFor(event, JOURNAL));
  if (correlation > 0.1 || correlation < -0.1) {
    console.log(event + ":", correlation)
  }
}

for (let entry of JOURNAL) {
  if (entry.events.includes("peanuts") &&
    !entry.events.includes("brushed teeth")) {
    entry.events.push('peanut teeth');
  }
}
console.log(phi(tableFor("peanut teeth", JOURNAL)));