Linear Algebra

The geometry and computation that underlies all of ML.

18 articles

  1. 01

    Essence of Linear Algebra (1): The Essence of Vectors — More Than Just Arrows

    Vectors are everywhere -- from GPS navigation to Netflix recommendations. This chapter builds your intuition from arrows …

    30 min
  2. 02

    Essence of Linear Algebra (2): Linear Combinations and Vector Spaces

    If vectors are building blocks, linear combinations are the blueprint. This chapter develops the five concepts that the …

    28 min
  3. 03

    Essence of Linear Algebra (3): Matrices as Linear Transformations

    Matrices are not tables of numbers -- they are machines that transform space. This chapter shows you how to see …

    30 min
  4. 04

    Essence of Linear Algebra (4): The Secrets of Determinants

    Determinants are not just tedious calculations -- they measure how much a transformation stretches or compresses space. …

    26 min
  5. 05

    Essence of Linear Algebra (5): Linear Systems and Column Space

    When does Ax = b have a solution? How many? The honest answer is geometric: it depends on whether b lives inside the …

    32 min
  6. 06

    Essence of Linear Algebra (6): Eigenvalues and Eigenvectors

    Some special vectors survive a matrix transformation with their direction intact -- they only get scaled. These …

    32 min
  7. 07

    Essence of Linear Algebra (7): Orthogonality and Projections — When Vectors Mind Their Own Business

    Orthogonality is what makes GPS work, noise-canceling headphones cancel, and JPEG compress. This chapter builds …

    28 min
  8. 08

    Essence of Linear Algebra (8): Symmetric Matrices and Quadratic Forms — The Best Matrices in Town

    Symmetric matrices are the 'nicest' matrices in linear algebra: real eigenvalues, orthogonal eigenvectors, and perfect …

    26 min
  9. 09

    Essence of Linear Algebra (9): Singular Value Decomposition — The Crown Jewel of Linear Algebra

    SVD decomposes any matrix -- not just square or symmetric ones. From image compression to Netflix recommendations, from …

    30 min
  10. 10

    Essence of Linear Algebra (10): Matrix Norms and Condition Numbers — Is Your Linear System Healthy?

    The condition number is a 'health report' for a linear system — it tells you whether tiny input errors will explode into …

    30 min
  11. 11

    Essence of Linear Algebra (11): Matrix Calculus and Optimization — The Engine Behind Machine Learning

    Adjusting the shower temperature is a tiny version of training a neural network: you change a parameter based on an …

    30 min
  12. 12

    Essence of Linear Algebra (12): Sparse Matrices and Compressed Sensing — Less Is More

    Sparsity is everywhere: JPEG photos, MRI scans, genomic data. Compressed sensing exploits this to recover signals from …

    28 min
  13. 13

    Essence of Linear Algebra (13): Tensors and Multilinear Algebra

    From scalars to high-dimensional data cubes -- tensors generalize vectors and matrices to arbitrary dimensions. Learn CP …

    40 min
  14. 14

    Essence of Linear Algebra (14): Random Matrix Theory

    Fill a huge matrix with random numbers, compute its eigenvalues, and watch stunning regularity emerge from chaos. Learn …

    30 min
  15. 15

    Essence of Linear Algebra (15): Linear Algebra in Machine Learning

    Machine learning speaks linear algebra as its native language. From PCA to SVMs, from matrix factorization in …

    38 min
  16. 16

    Essence of Linear Algebra (16): Linear Algebra in Deep Learning

    Deep learning is large-scale matrix computation. From backpropagation as the chain rule in matrix form, to im2col …

    34 min
  17. 17

    Essence of Linear Algebra (17): Linear Algebra in Computer Vision

    Images are matrices, geometric transformations are matrix multiplications, camera imaging is a projective map, and 3D …

    30 min
  18. 18

    Essence of Linear Algebra (18): Frontiers and Summary

    Series finale: quantum gates as unitary matrices, graph convolution as Laplacian filtering, attention as soft retrieval, …

    40 min