Univariate cost function

Machine learning course on coursera

by de Montalembert Jonathan

JavaScript

// univariate cost function
function cost(x, y, theta_0, theta_1) {
  var m = x.length;
  var prediction = 0;
  x.forEach(function(xi, i) {
    prediction += Math.pow((theta_0 + xi * theta_1) - y[i], 2)
  });
  return prediction / (2 * m)
}

console.log(cost([1, 2], [2, 4], 0, 2))