Numerical Analysis
Error, root-finding, interpolation, and numerical linear algebra/ODEs -- the practical algorithms behind approximate solutions, and why they work.
Free to read now, no account needed: Readiness: what numerical analysis leans on. Create a free account to open the other chapters, take the quizzes and keep your progress.
- Chapter overview
- Taylor's theorem and the Lagrange remainder, revisited ~9 min
- Sequences and the limit of a sequence, revisited ~8 min
- Matrix algebra and Gaussian elimination, revisited ~9 min
- Eigenvalues and eigenvectors, revisited ~9 min
- Vector norms, revisited ~7 min
- Euler's method and the idea of a numerical ODE solver, revisited ~8 min
- Chapter wrap-up
1 Foundations of Numerical Computing π
Create a free account to open this chapter.
- Exact vs. approximate solutions ~10 min
- Algorithms, convergence, and rate of convergence ~11 min
- Sources of error: round-off and truncation ~10 min
- Absolute error, relative error, and significant digits ~12 min
- Floating-point representation and machine epsilon ~13 min
- Overflow, underflow, and rounding modes ~11 min
- Catastrophic cancellation and loss of significance ~12 min
- Conditioning: how sensitive is the problem? ~13 min
- Stability: how sensitive is the algorithm? ~13 min
2 Root-Finding for Nonlinear Equations π
Create a free account to open this chapter.
- Bracketing a root: the Intermediate Value Theorem in practice ~12 min
- The Bisection Method ~16 min
- Fixed-point iteration and the cobweb diagram ~14 min
- Convergence of fixed-point iteration: the contraction condition ~14 min
- Newton's Method: derivation from the tangent line ~16 min
- Newton's Method: convergence order and failure modes ~15 min
- The Secant Method ~14 min
- The Method of False Position ~13 min
- MΓΌller's Method and roots of polynomials ~15 min
- Choosing a root-finding method ~12 min
3 Polynomial Interpolation π
Create a free account to open this chapter.
- The interpolation problem: existence and uniqueness ~13 min
- The Lagrange form of the interpolating polynomial ~15 min
- Newton's divided-difference form ~18 min
- Neville's method ~14 min
- The interpolation error formula ~15 min
- Equally spaced nodes and the Runge phenomenon ~16 min
- Chebyshev nodes: taming the Runge phenomenon ~15 min
- Hermite interpolation ~15 min
- Extrapolation: why it's riskier than interpolation ~13 min
4 Spline Interpolation π
Create a free account to open this chapter.
- Why one high-degree polynomial can go wrong ~12 min
- Piecewise linear and piecewise quadratic splines ~15 min
- Cubic splines: setting up the system ~20 min
- Natural boundary conditions ~22 min
- Clamped boundary conditions ~18 min
- Continuity of position, slope, and curvature ~16 min
- Solving the spline system: tridiagonal solvers ~17 min
- Parametric curves from splines ~15 min
5 Numerical Differentiation π
Create a free account to open this chapter.
- Forward and backward difference formulas ~14 min
- The central difference formula ~14 min
- Deriving difference formulas from Taylor series ~18 min
- Truncation error vs. round-off error in differentiation ~16 min
- Choosing the step size h: the U-shaped error curve ~18 min
- Richardson extrapolation ~20 min
6 Numerical Integration π
Create a free account to open this chapter.
- The midpoint and trapezoidal rules: error bounds ~14 min
- Simpson's rule and degree of precision ~20 min
- Composite rules and error bounds ~18 min
- Romberg integration ~18 min
- Adaptive quadrature ~16 min
- Gaussian quadrature: nodes and weights ~18 min
- Improper integrals, numerically ~14 min
- Multiple integrals, briefly ~12 min
- Trigonometric approximation and the idea of the FFT ~12 min
- Choosing a quadrature method ~12 min
7 Direct Methods for Linear Systems π
Create a free account to open this chapter.
- Gaussian elimination, revisited numerically ~10 min
- Partial pivoting and why it's necessary ~20 min
- Operation counts: why elimination is $O(n^3)$ ~12 min
- LU factorization from elimination ~15 min
- Cholesky factorization for symmetric positive-definite systems ~15 min
- Vector and matrix norms ~14 min
- The condition number of a matrix ~16 min
- Iterative refinement ~14 min
- Special matrix structures: banded and tridiagonal systems ~14 min
8 Iterative Methods for Linear Systems π
Create a free account to open this chapter.
- Why iterate instead of solving directly? ~11 min
- The Jacobi method ~18 min
- The Gauss-Seidel method ~15 min
- Successive over-relaxation (SOR) ~16 min
- Convergence: diagonal dominance and spectral radius ~17 min
- The Conjugate Gradient method ~17 min
- Direct vs. iterative: choosing a method ~12 min
9 Least Squares and Curve Fitting π
Create a free account to open this chapter.
- Overdetermined systems and the least-squares problem ~14 min
- The normal equations ~14 min
- Why the normal equations can be numerically dangerous ~18 min
- Least squares via QR factorization ~20 min
- Polynomial and nonlinear curve fitting ~16 min
- Orthogonal polynomials as a stable fitting basis ~16 min
- Residuals and goodness of fit ~15 min
10 Numerical Eigenvalue Problems π
Create a free account to open this chapter.
- Why not just use the characteristic polynomial? ~12 min
- The Power Method ~16 min
- The Rayleigh quotient and accelerated convergence ~20 min
- The Inverse Power Method and Shifted Inverse Iteration ~18 min
- Deflation ~16 min
- Householder Reflections and Reduction to Hessenberg Form ~18 min
- The QR Algorithm ~20 min
- Computing the SVD Numerically ~18 min
- Choosing an Eigenvalue Method ~14 min
11 Numerical Solutions of Nonlinear Systems π
Create a free account to open this chapter.
- Fixed Points for Functions of Several Variables ~16 min
- Newton's Method for Systems: the Jacobian ~22 min
- Quasi-Newton (Broyden's) Methods ~18 min
- Steepest Descent as a Globalization Strategy ~18 min
- Homotopy and Continuation Methods ~18 min
- Golden-Section Search: the One-Dimensional Case ~16 min
12 Initial-Value Problems for ODEs π
Create a free account to open this chapter.
- Well-posedness of the initial-value problem, revisited ~14 min
- Euler's method, revisited numerically ~15 min
- Local vs. global truncation error, made formal ~20 min
- Higher-order Taylor methods ~16 min
- Runge-Kutta methods: RK2 and the midpoint method ~18 min
- RK4 ~22 min
- Adaptive step size: the Runge-Kutta-Fehlberg method ~20 min
- Multistep methods: Adams-Bashforth and Adams-Moulton ~20 min
- Predictor-corrector methods ~16 min
- Absolute stability and stiff equations ~24 min
- Systems and higher-order equations ~18 min
13 Boundary-Value Problems for ODEs π
Create a free account to open this chapter.
- What makes a BVP different from an IVP ~16 min
- The Linear Shooting Method ~22 min
- The Shooting Method for Nonlinear Problems ~20 min
- Finite-Difference Methods for BVPs ~20 min
- The Rayleigh-Ritz Method, Briefly ~14 min
14 A Survey of Numerical Methods for PDEs π
Create a free account to open this chapter.
- Classifying PDEs for numerical purposes ~16 min
- Finite differences for the heat equation, revisited ~14 min
- Finite differences for the wave equation, revisited ~14 min
- Finite differences for Laplace's equation, revisited ~16 min
- Choosing a numerical PDE method ~14 min
- Capstone: building a numerical solution end to end ~22 min