Clustering & Dimensionality Reduction

Find structure in unlabelled data with k-means, DBSCAN, GMMs, PCA, t-SNE and UMAP — and know when each one lies to you

Learn k-means, hierarchical clustering, DBSCAN and Gaussian mixtures, how to choose k and evaluate clusters without labels, and how PCA, t-SNE and UMAP compress high-dimensional data — with a worked PCA example and interview traps.

Practice questions (6)

• k-means Local Minimum by Hand

  Intermediate · Free
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• Computing and Interpreting Silhouette Scores

  Intermediate
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• Choosing Between k-means, DBSCAN and GMM

  Intermediate
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• PCA on a Small Dataset

  Intermediate
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• Misreading a t-SNE Plot

  Intermediate
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Quizzes (1)