Appendix I — Mapping to Axler and to Boyd & Vandenberghe

This appendix maps our 40 chapters to two further classics that this book is in conversation with, each representing a different philosophy:

  • Sheldon Axler, Linear Algebra Done Right (Springer; the 4th edition is freely readable online). The rigorous, proof-first counterpart. Axler develops the entire subject through linear maps on abstract vector spaces and famously delays determinants to the very last chapter, deriving eigenvalue theory without them.
  • Stephen Boyd & Lieven Vandenberghe, Introduction to Applied Linear Algebra: Vectors, Matrices, and Least Squares (Cambridge; free PDF at vmls-book.stanford.edu, hence "VMLS"). The applied counterpart — organized around vectors, matrices, and least squares, with worked examples from data fitting, control, and machine learning, and almost no abstract proof.

Because these books are organized so differently from ours, the mappings are topic-level, and many are approximate — flagged [verify]. Axler's section structure in particular was reorganized between the 3rd and 4th editions; confirm against your copy.

I.1 The two ordering philosophies to keep in mind

Before the table, the two structural facts that drive most of the mismatches:

  • Axler is determinant-last and proof-first. He treats eigenvalues, the spectral theorem, and operator theory before determinants, which appear only in his final chapter (with the trace). This is the opposite of both this book (determinants in Part II) and Strang (determinants in the middle). An Axler-aligned reader should expect our Chapter 11 to have no early counterpart in Axler, and our eigenvalue chapters (23–28) to be where Axler's core lives.
  • Boyd is applied and least-squares-centric. VMLS has three partsVectors (chs. 1–5), Matrices (chs. 6–11), and Least Squares (chs. 12–19) — and deliberately omits determinants, eigenvalues, the SVD, and abstract vector spaces to stay focused on what a data/engineering practitioner uses most. So several of our later chapters have no Boyd counterpart at all, marked "—".

I.2 Chapter-by-chapter correspondence

This book (chapter · topic) Axler, LADR (topic) Boyd–Vandenberghe (VMLS topic)
1. What Is Linear Algebra? Preface / Ch. 1 intro [verify] Ch. 1 Vectors (intro)
2. Vectors 1A $\mathbb{R}^n$, $\mathbb{C}^n$ Ch. 1 Vectors; Ch. 3 norm/distance
3. Systems of Linear Equations (not central; via linear maps) [verify] Ch. 8 Linear equations; Ch. 11 solving $A\mathbf{x}=\mathbf{b}$
4. Gaussian Elimination & Row Reduction (not emphasized) [verify] Ch. 11 (matrix inverses, solving) [verify]
5. Vector Spaces 1B–1C Definition and subspaces (concrete only; no axiomatic treatment) —
6. Subspaces, Span, Linear Independence 2A Span and independence; 2B bases Ch. 5 Linear independence; Ch. 5 basis
7. Matrices as Functions 3A–3B Linear maps; matrix of a map Ch. 6 Matrices; Ch. 10 matrix-vector product
8. Matrix Operations 3C Matrix multiplication; 3D Ch. 6, Ch. 10 (products, transpose)
9. The Inverse Matrix 3D Invertibility, isomorphisms Ch. 11 Matrix inverses
10. LU & PLU Decomposition (not covered) [verify] Ch. 11 (factor-solve perspective) [verify]
11. The Determinant Ch. 10 (last chapter!) — Trace and determinant — (omitted in VMLS)
12. Application: Computer Graphics (not covered) (not covered) —
13. Column Space & Null Space 3B Range and null space (kernel) Ch. 5; Ch. 8 (range/nullspace via least squares) [verify]
14. Row Space, Left Null Space, Rank–Nullity 3B Fundamental theorem of linear maps (rank–nullity) Ch. 10 (rank); not the four-subspace framing [verify]
15. Dimension, Basis, Coordinates 2C Dimension Ch. 5 (basis, dimension)
16. Change of Basis 3F Change of basis; 10A [verify] (light) [verify]
17. Application: Linear Regression (not an applications book) Ch. 12–13 Least squares & data fitting (core VMLS)
18. Dot Products, Norms, Angles 6A Inner products and norms Ch. 3 Norm, distance, angle; Ch. 4
19. Orthogonal Projection 6B Orthonormal bases; projections Ch. 12 (least squares = projection)
20. Gram–Schmidt & QR 6B Gram–Schmidt Ch. 5 / Ch. 10 QR factorization; Ch. 12
21. Orthogonal Matrices & Rotations 7 (isometries); 6 orthonormal Ch. 7 Matrix examples (rotations) [verify]
22. Application: Fourier Series 6B (orthonormal expansions) [verify] (not covered) —
23. Eigenvalues & Eigenvectors 5A–5B Eigenvalues, invariant subspaces — (omitted in VMLS)
24. The Characteristic Polynomial 5 / 8 (Axler develops eigenvalues without det first)
25. Diagonalization 5C Eigenspaces and diagonal matrices
26. Complex Eigenvalues 8 Operators on complex/real vector spaces
27. The Spectral Theorem 7A–7B The spectral theorem (a high point of Axler)
28. Positive Definite & Quadratic Forms 7C Positive operators; isometries (touched via least squares / Gram matrix) [verify]
29. Application: PageRank (not covered) (not covered) —
30. Singular Value Decomposition 7E–7F The SVD (added prominence in 4th ed.) [verify] — (omitted in VMLS)
31. SVD Applications (briefly, via SVD section) [verify]
32. Principal Component Analysis (not covered) (PCA-adjacent via least squares) [verify]
33. Application: Machine Learning (not an applications book) Ch. 13–14 (classification, fitting) [verify]
34. Inner Product Spaces Ch. 6 (the core of Axler's geometry) Ch. 3 (concrete inner products only)
35. Linear Transformations & Abstract Vector Spaces Ch. 3 (the spine of the whole book) (concrete maps only) —
36. Jordan Normal Form 8D Generalized eigenvectors; nilpotents (Axler's route to Jordan-type results) [verify]
37. Matrix Exponential & Systems of ODEs (not covered) [verify] (not covered) —
38. Numerical Linear Algebra (not covered; Axler is non-numerical) Ch. 11–12 (conditioning touched lightly) [verify]
39. Capstone VMLS exercises / applications
40. Where Linear Algebra Goes Next Epilogue [verify] Appendix / further directions [verify]

I.3 How to use each book alongside this one

If you are a math major reading Axler in parallel: treat our geometry-first chapters as the intuition layer beneath Axler's proofs. Our Chapters 5, 7, and 35 (vector spaces, matrices-as-maps, abstract transformations) are the on-ramps to his Chapters 1–3; our Chapters 23–28 line up with his eigenvalue and spectral-theorem core (Axler's Chapters 5–7); and his determinant-last philosophy means you should read our Chapter 11 as a geometric account he deliberately postpones. Axler's payoff — that you can do eigenvalue theory without determinants — is visible in how little our eigenvalue chapters actually lean on Chapter 11.

If you are a CS/data-science reader keeping Boyd open for applications: VMLS is the best companion for the applied chapters — Chapter 17 (regression), Chapters 18–20 (orthogonality and least squares), and Chapter 33 (machine learning) map directly onto its least-squares core (VMLS Parts II–III). But VMLS deliberately stops short of determinants, eigenvalues, the SVD, and abstract spaces — so for Chapters 11 and 23–36 you will want Strang (Appendix H) or this book alone. Think of Boyd as the deep, practical treatment of half this book — the half a practitioner uses daily — done with exceptional clarity.

A note on honesty in this table. Where a cell says "not covered" or "—," that is a real scope difference, not an oversight: Axler omits applications and numerics by design, and Boyd omits eigenvalues, the SVD, determinants, and abstraction by design. The [verify] flags mark places where the section-level fit depends on the edition or where a topic is present but not in a cleanly corresponding unit. Trust the topic names over the structure.