1. 9/3 |
Tue |
Course overview. Probability review. |
Slides. Compressed slides. Reading: MIT short videos and exercises on probability (go to Unit 4). Khan academy probability lessons (a bit more basic). Chapters 1-3 of Probability and Computing with content and excersises on basic probability, expectation, variance, and concentration bounds. |
Randomized Methods, Sketching & Streaming |
2. 9/5 |
Thu |
Linearity of expectation and variance. Estimating set size by counting duplicates. Markov's inequality. Random hashing for efficient lookup. |
Slides. Compressed slides. Reading: Chapters 1-3 of Probability and Computing with content and excersises on basic probability, expectation, variance, and concentration bounds. |
3. 9/10 |
Tue |
Collision-free hashing. 2-level hashing. 2-universal and pairwise independent hashing. |
Slides. Compressed slides. Reading: Chapter 2.2 of Foundations of Data Science with content on Markov's inequality and Chebyshev's inequality. Exercises 2.1-2.6. Chapters 1-3 of Probability and Computing with content and excersises on basic probability, expectation, variance, and concentration bounds. Some notes (Arora and Kothari at Princeton) proving that the ax+b mod p hash function described in class in 2-universal.
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4. 9/12 |
Thu |
Hashing for load balancing. Chebyshev's inequality. The union bound. Maybe start on exponential concentration bounds. |
Slides. Compressed slides. Reading: Chapter 2.2 of Foundations of Data Science with content on Markov's inequality and Chebyshev's inequality. Exercises 2.1-2.6. Chapters 1-3 of Probability and Computing with content and excersises on basic probability, expectation, variance, and concentration bounds.
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5. 9/17 |
Tue |
Exponential concentration bounds and the central limit theorem. |
Slides. Compressed slides. Reading: Chapter 4 of Probability and Computing on exponential concentration bounds. Some notes (Goemans at MIT) showing how to prove exponential tail bounds using the moment generating function + Markov's inequality approach discussed in class. |
6. 9/19 |
Thu |
Finish up applications of exponential concentration bounds. Bloom Filters. |
Slides. Compressed slides. Reading: Chapter 4 of Mining of Massive Datasets, with content on Bloom filters. See here for full Bloom filter analysis. See Wikipedia for a discussion of the many bloom filter variants, including counting Bloom filters, and Bloom filters with deletions. |
7. 9/24 |
Tue |
Finish up Bloom filters. Start on streaming algorithms and frequent elements estimation. |
Slides. Compressed slides. Reading: Chapter 4 of Mining of Massive Datasets, with content on Bloom filters. Notes (Amit Chakrabarti at Dartmouth) on streaming algorithms. See Chapters 1 and 5 for frequent elements. Some more notes on the frequent elements problem. |
8. 9/26 |
Thu |
Frequent elements estimation via Count-min sketch. Min-Hashing for Distinct elements. |
Slides. Compressed slides. Reading: Notes (Amit Chakrabarti at Dartmouth) on streaming algorithms. See Chapters 1 and 5 for frequent elements. Some more notes on the frequent elements problem. A website with lots of resources, implementations, and example applications of count-min sketch. Chapter 4 of Mining of Massive Datasets, with content on distinct elements counting.
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9. 10/1 |
Tue |
Finish up distinct elements counting. The median trick. Distinct elements in pratice: Flajolet-Martin and HyperLogLog. |
Slides. Compressed slides. Reading: Chapter 4 of Mining of Massive Datasets, with content on distinct elements counting. The 2007 paper introducing the popular HyperLogLog distinct elements algorithm.
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10. 10/3 |
Thu |
Start on Jaccard similarity, fast similarity search, and locality sensitive hashing |
Slides. Compressed slides. Reading: Chapter 3 of Mining of Massive Datasets, with content on Jaccard similarity, MinHash, and locality sensitive hashing.
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11. 10/8 |
Tue |
Finish up locality sensitive hashing. Start on compressing high dimensional data -- low-distortion embeddings and the Johnson Lindenstrauss Lemma.
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Slides. Compressed slides. Reading: Chapter 3 of Mining of Massive Datasets, with content on Jaccard similarity, MinHash, and locality sensitive hashing. Chapter 2.7 of Foundations of Data Science on the Johnson-Lindenstrauss lemma. Notes on the JL-Lemma (Anupam Gupta (CMU). Linear Algebra Review: Khan academy. |
12. 10/10 |
Thu |
Proof of the Johnson Lindenstrauss Lemma. Example application to clustering.
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Slides. Compressed slides. Reading: Chapter 2.7 of Foundations of Data Science on the Johnson-Lindenstrauss lemma. Notes on the JL-Lemma (Anupam Gupta (CMU). Sparse random projections which can be multiplied by more quickly. |
10/15 |
Tue |
No Class. Monday class schedule followed. |
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13. 10/17 |
Thu |
Midterm Review. Midterm in the evening. 7-9pm in ILCN 151, 211, 331. |
Study guide and review questions. |
Spectral Methods |
10/22 |
Tue |
No Class. Professor Traveling. |
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14. 10/24 |
Thu |
Intro to principal component analysis, low-rank approximation, data-dependent dimensionality reduction. Orthogonal bases and projection matrices. Dual column/row view of low-rank approximation. |
Slides. Compressed slides.
Reading: Chapter 3 of Foundations of Data Science and Chapter 11 of Mining of Massive Datasets on low-rank approximation and the SVD. Some good videos for linear algebra review. Some other good videos overviewing the SVD and related topics (like orthogonal projection and low-rank approximation). |
15. 10/29 |
Tue |
Best fit subspaces and optimal low-rank approximation via eigendecomposition. |
Slides. Compressed slides. Reading: Proof that optimal low-rank approximation can be found greedily (see Section 1.1). Chapter 3 of Foundations of Data Science and Chapter 11 of Mining of Massive Datasets on low-rank approximation. |
16. 10/31 |
Thu |
Finish up optimal low-rank approximation via eigendecomposition. Eigenvalues as a measure of low-rank approximation error. General linear algebra review.
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Slides. Compressed slides.
Reading: Chapter 3 of Foundations of Data Science and Chapter 11 of Mining of Massive Datasets on low-rank approximation. |
11/05 |
Tue |
No Class. Election Day. |
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17. 11/07 |
Thu |
The singular value decomposition and connections to low-rank approximation. Applications of low-rank approximation beyond compression. Matrix completion and entity embeddings.
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Slides. Compressed slides.
Reading: Notes on SVD and its connection to eigendecomposition/PCA (Roughgarden and Valiant at Stanford). Notes on matrix completion, with proof of recovery under incoherence assumptions (Jelani Nelson at Harvard). Levy Goldberg paper on word embeddings as implicit low-rank approximation. |
18. 11/12 |
Tue |
Spectral graph theory and spectral clustering. |
Slides. Compressed slides. Reading: Chapter 10.4 of Mining of Massive Datasets on spectral graph partitioning. For a lot more interesting material on spectral graph methods see Dan Spielman's lecture notes. Great notes on spectral graph methods (Roughgarden and Valiant at Stanford). |
19. 11/14 |
Thu |
The stochastic block model. |
Slides. Compressed slides. Reading: Dan Spielman's lecture notes on stochastic block model, including matrix concentration + David-Kahan perturbation analysis.. Further stochastic block model notes (Alessandro Rinaldo at CMU). A survey of the vast literature on the stochastic block model, beyond the spectral methods discussed in class (Emmanuel Abbe at Princeton). |
20. 11/19 |
Tue |
Computing the SVD: power method. |
Slides. Compressed slides. Reading: Chapter 3.7 of Foundations of Data Science on the power method for SVD. Some notes on the power method. (Roughgarden and Valiant at Stanford). |
Optimization |
21. 11/21 |
Thu |
Finish up power method analysis. Krylov methods. Connection to random walks and Markov chains. Briefy intro to continuous optimization. |
Slides. Compressed slides. Reading: Chapter 3.7 of Foundations of Data Science on the power method for SVD. Some notes on the power method. (Roughgarden and Valiant at Stanford). Multivariable calc review, e.g., through: Khan academy |
11/26 |
Tue |
No Class. |
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11/28 |
Thu |
No Class. Thanksgiving recess. |
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22. 12/03 |
Tue |
Intro to gradient descent and its analysis for convex Lipschitz functions. |
Reading: Chapters I and III of these notes (Hardt at Berkeley). |
23. 12/05 |
Thu |
Constrained optimization and projected gradient descent. |
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24. 12/10 |
Tue |
Online gradient descent and application to the analysis of stochastic gradient descent. Course conclusion/review. |
Reading: Short notes, proving regret bound for online gradient descent. A good book (by Elad Hazan) on online optimization, including online gradient descent and connection to stochastic gradient descent. |
12/18, 10:30am - 12:30pm |
Wed |
Final Exam. |
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