Machine Learning: Difference between revisions

From Adam Colton
Jump to navigation Jump to search
Line 27: Line 27:
=== Cost Function ===
=== Cost Function ===
h<sub>&Theta;</sub>(x) = &Theta;<sub>0</sub> + &Theta;<sub>1</sub>x
h<sub>&Theta;</sub>(x) = &Theta;<sub>0</sub> + &Theta;<sub>1</sub>x
sum of square error as our cost function. He's using 1/2m rather than 1/m, I'm not sure why.


=== Cost Function - Intuition : 1===
=== Cost Function - Intuition : 1===

Revision as of 00:52, 23 April 2013

Week 1 - Intro

What is Machine Learning

  • Checkers playing computer (Arthur Samuel)

Supervised Learning

Right answer is provided. Types of problems

  • Regression
  • Classification

Unsupervised Learning

The data has no "correct answer"

Cocktail party algorithm

Week 1 - Linear Regression with One variable

Model Representation

Working with housing prices in Portland as our dataset.

Symbols used

  • m - number of training examples
  • x - input variables
  • y - output variable
  • h - hypothesis (function h(x) = y)

Univariate linear regression

Cost Function

hΘ(x) = Θ0 + Θ1x

sum of square error as our cost function. He's using 1/2m rather than 1/m, I'm not sure why.

Cost Function - Intuition : 1

Cost Function - Intuition : 2

Gradient Descent

Gradient Descent Intuition

Gradient Descent for Linear Regression