It is very useful for

In a real-world environment, you can imagine that a robot or an

Do you ever wonder how we get the data that we use in our supervised machine learning algorithms?

We always seem to have a nice CSV or a table, complete with Xs and corresponding Ys.

If you haven’t been involved in acquiring data yourself, you might not have thought about this, but someone has to make this data!

Those “Y”s have to come from somewhere, and a lot of the time that involves manual labor.

Sometimes, you don’t have access to this kind of information or it is infeasible or costly to acquire.

But you still want to have some idea of the structure of the data. If you're doing

This is where unsupervised machine learning comes into play.

In this course we are first going to talk about clustering. This is where instead of training on labels, we try to create our own labels! We’ll do this by grouping together data that looks alike.

There are 2 methods of clustering we’ll talk about:

Next, because in machine learning we like to talk about probability distributions, we’ll go into

One interesting fact is that under certain conditions, Gaussian mixture models and k-means clustering are exactly the same! We’ll prove how this is the case.

All the algorithms we’ll talk about in this course are staples in machine learning and data science, so if you want to know how to automatically find patterns in your data with data mining and pattern extraction, without needing someone to put in manual work to label that data, then this course is for you.

All the materials for this course are FREE. You can download and install Python, Numpy, and Scipy with simple commands on Windows, Linux, or Mac.

This course focuses on

NOTES:

All the code for this course can be downloaded from my github:

https://github.com/lazyprogrammer/machine_learning_examples

In the directory: unsupervised_class

Make sure you always "git pull" so you have the latest version!

HARD PREREQUISITES / KNOWLEDGE YOU ARE ASSUMED TO HAVE:

- calculus
- linear algebra
- probability
- Python coding: if/else, loops, lists, dicts, sets
- Numpy coding: matrix and vector operations, loading a CSV file

TIPS (for getting through the course):

- Watch it at 2x.
- Take handwritten notes. This will drastically increase your ability to retain the information.
- Write down the equations. If you don't, I guarantee it will just look like gibberish.
- Ask lots of questions on the discussion board. The more the better!
- Realize that most exercises will take you days or weeks to complete.
- Write code yourself, don't just sit there and look at my code.

- Introduction and Outline (02:22) (FREE preview available)
- What is unsupervised learning used for? (04:32)
- Why Use Clustering? (04:11)
- How to Succeed in this Course (03:13)

- An Easy Introduction to K-Means Clustering (07:06)
- Visual Walkthrough of the K-Means Clustering Algorithm (02:58)
- Soft K-Means (05:41)
- The K-Means Objective Function (01:39)
- Soft K-Means in Python Code (10:03)
- Visualizing Each Step of K-Means (02:18)
- Examples of where K-Means can fail (07:32)
- Disadvantages of K-Means Clustering (02:13)
- How to Evaluate a Clustering (Purity, Davies-Bouldin Index) (06:33)
- Using K-Means on Real Data: MNIST (05:00)
- One Way to Choose K (05:15)
- K-Means Application: Finding Clusters of Related Words (08:38)

- Visual Walkthrough of Agglomerative Hierarchical Clustering (02:35)
- Agglomerative Clustering Options (03:38)
- Using Hierarchical Clustering in Python and Interpreting the Dendrogram (04:38)
- Application: Evolution (14:00)
- Application: Donald Trump vs. Hillary Clinton Tweets (18:34)

- Description of the Gaussian Mixture Model and How to Train a GMM (03:04)
- Comparison between GMM and K-Means (01:44)
- Write a Gaussian Mixture Model in Python Code (09:59)
- Practical Issues with GMM / Singular Covariance (02:55)
- Kernel Density Estimation (02:11)
- Expectation-Maximization (02:01)
- Future Unsupervised Learning Algorithms You Will Learn (01:01)

- What is the Appendix? (02:48)
- Windows-Focused Environment Setup 2018 (20:20)
- How to install Numpy, Scipy, Matplotlib, Pandas, IPython, Theano, and TensorFlow (17:22)
- Is this for Beginners or Experts? Academic or Practical? Fast or slow-paced? (22:04)
- How to Code Yourself (part 1) (15:54)
- How to Code Yourself (part 2) (09:23)
- What order should I take your courses in? (part 1) (11:18)
- What order should I take your courses in? (part 2) (16:07)
- Python 2 vs Python 3 (04:38)
- How to Succeed in this Course (Long Version) (10:24)
- Where to get discount coupons and FREE deep learning material (02:20)