This chapter will cover the following recipes:
- Using k-means to cluster data
 - Optimizing the number of centroids
 - Assessing cluster correctness
 - Using MiniBatch k-means to handle more data
 - Quantizing an image with k-means clustering
 - Finding the closest objects in the feature space
 - Probabilistic clustering with Gaussian Mixture Models
 - Using k-means for outlier detection
 - Using KNN for regression