Unsupervised Learning & K-means

• Clustering Algorithms, K-means Algorithm
• Centroids
• K-means for non-separated clusters
• Random initialisation
• Elbow method

Dimensionality Reduction

• 2D -> 1D
• Data Compression to speedup training as well as visualizations of complex datasets
• Indexes (e.g. GDP, Human Development Index)
• Principal Component Analysis (PCA), projection
• Data Preprocesing. Scaling, normalization
• [U, S, V] = svd(sigma)
• U = covariance matrix
• Reconstruction from compressed representation