TylerL-uxai

// Bonfire: Pig Latin
// Author: @tylerl-uxai
// Challenge: http://www.freecodecamp.com/challenges/bonfire-pig-latin
// Learn to Code at Free Code Camp (www.freecodecamp.com)

function translate(str) {
  var regex = /[aeiou]/gi;
  if (str[0].match(regex)){ 
    return str + "way";
  } else if (str[1].match(regex)){

TylerL-uxai

// Bonfire: Search and Replace
// Author: @tylerl-uxai
// Challenge: http://www.freecodecamp.com/challenges/bonfire-search-and-replace
// Learn to Code at Free Code Camp (www.freecodecamp.com)
// Rewritten by myself with the help of https://github.com/FreeCodeCamp/FreeCodeCamp/wiki/Bonfire-Search-and-Replace

function myReplace(str, before, after) {
  var i = str.indexOf(before);
  
  if (str[i] == str[i].toUpperCase()){

TylerL-uxai

// Bonfire: Where art thou
// Author: @tylerl-uxai
// Challenge: http://www.freecodecamp.com/challenges/bonfire-where-art-thou
// Learn to Code at Free Code Camp (www.freecodecamp.com)
// Rewritten myself with help from https://github.com/FreeCodeCamp/FreeCodeCamp/wiki/Bonfire-Where-art-thou

function where(collection, source) {
// speed test
  var keys = Object.keys( source ); // returns the keys to the variable
  

TylerL-uxai

// Bonfire: Roman Numeral Converter
// Author: @tylerl-uxai
// Challenge: http://www.freecodecamp.com/challenges/bonfire-roman-numeral-converter
// Learn to Code at Free Code Camp (www.freecodecamp.com)
// re-wrote by myself with the aid of http://wulkan.me/bonfire-roman-numeral-converter/

function convert(num) {
  var romanNumerals = '',
      decimals = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1],
      numerals = ['M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I'];

TylerL-uxai

// Bonfire: Diff Two Arrays
// Author: @tylerl-uxai
// Challenge: http://www.freecodecamp.com/challenges/bonfire-diff-two-arrays
// Learn to Code at Free Code Camp (www.freecodecamp.com)
// with the help of http://wulkan.me/bonfire-diff-two-arrays/ and https://github.com/pfilippi24
function diff(arr1, arr2) {
  // Same, same; but different.

  return arr1.concat(arr2).filter(function(val){
    return !(arr1.indexOf(val)>=0 && arr2.indexOf(val) >=0);

TylerL-uxai

function p = predict(theta, X)
%PREDICT Predict whether the label is 0 or 1 using learned logistic 
%regression parameters theta
%   p = PREDICT(theta, X) computes the predictions for X using a 
%   threshold at 0.5 (i.e., if sigmoid(theta'*x) >= 0.5, predict 1)

m = size(X, 1); % Number of training examples

% You need to return the following variables correctly
p = zeros(m, 1);

TylerL-uxai

Running Gradient Descent ...

ans =

   32.0727

Theta found by gradient descent: 0.000000 0.000000 
For population = 35,000, we predict a profit of 0.000000
For population = 70,000, we predict a profit of 0.000000

TylerL-uxai

function J = computeCost(X, y, theta)
%COMPUTECOST Compute cost for linear regression
%   J = COMPUTECOST(X, y, theta) computes the cost of using theta as the
%   parameter for linear regression to fit the data points in X and y

% Initialize some useful values
m = length(y); % number of training examples

% You need to return the following variables correctly 

TylerL-uxai

function [theta, J_history] = gradientDescent(X, y, theta, alpha, num_iters)
%GRADIENTDESCENT Performs gradient descent to learn theta
%   theta = GRADIENTDESENT(X, y, theta, alpha, num_iters) updates theta by 
%   taking num_iters gradient steps with learning rate alpha

% Initialize some useful values
m = length(y); % number of training examples
J_history = zeros(num_iters, 1);

for iter = 1:num_iters