Lecture Outlines/Supplementary Material (Fall'09)

This webpage contains lecture outlines for CO463/663. Summary of Notation and Basic Results. Be aware that this webpage is continually being polished/changed.

Lectures Date Subjects Covered Lecture Contents/Supplementary Materials
Lecture 24 Thurs. Dec. 3 Review
  • projection for multiple sets
  • review e.g.:
    • basic concepts of convex sets, functions
    • subdifferentials, normal cones, tangent cones, directional derivatives
    • sandwich and separation theorems
    • Fenchel conjugate, Fenchel dual
  • Lecture 23 Tues. Dec. 1 Convex Feasibility cont... (see Techniques of Variational Analysis, available online at UofW library)
  • Projection as a minimization problem
  • Attracting mappings and Fejer sequences
  • Convergence
  • Lecture 22 Thurs. Nov. 26 KKT Conditions and Convex Feasibility Problems
  • KKT:
    • (text Sect. 7.2) Karush-Kuhn-Tucker Theorem for equality and inequality general NLP.
    • Mangasarian-Fromovitz CQ (MFCQ)
    • Proof of KKT using the weakest CQ (tangent cone equals linearizing cone)
  • Convex Feas. Probs:
    • Existence/uniqueness of nearest points to a closed convex set; normal cone characterization
    • projection map and properties (monotone operator)
  • Lecture 21 Tues. Nov. 24 Fenchel Duality of convex programs, KKT
  • Fenchel duality of convex nonlinear program (NLP)
  • KKT conditions for a general nonlinear program
  • tangent cones, linearizing cones
  • Lectures 18-20 Thurs. Nov. 12-19 Generalized cone programs
  • SDP
  • Fenchel duality and Lagrangian duality
  • Lecture 17 Tues. Nov. 10 optimization problems with cone constraints
  • applications to general linear programming
  • Lecture 16 Thurs. Nov. 5 KKT
  • Karush-Kuhn-Tucker conditions for the convex case
  • Lecture 15 Tues. Nov. 3 further characterizations of optimality
  • relations: normal cone, subgradient cone, linearizing cone
  • Lecture 14 Thurs. Oct. 29 Normal Cones characterization of optimality
  • Examples
  • Theorems of the alternative
  • Lecture 13 Tues. Oct. 27 Set constrained optimization
  • sandwich theorem with proof using hyperplane separation
  • Lecture 12 Thurs. Oct. 22 Subgradients algebra; Fenchel duality for minimization
  • locally Lip. continuity; f' closed; subgradient convex, compact
  • Fenchel duality and sandwich theorems (For a Lagrange multiplier approach see e.g. MAA Lester Ford prize article by Pourciau, i.e. Bruce H. Pourciau, Modern multiplier rules, Amer. Math. Monthly 87 (1980), 433-452)
  • Lecture 11 Tues. Oct. 20 Fenchel-Legendre conjugate/duality;
  • support functions; directional derivatives; subgradients
  • subgradients/derivatives of eigenvalue functions
  • Lecture 10 Thurs. Oct. 15 Fenchel-Legendre transform; conjugate/duality; optimality conditions
  • More on support functions
  • f**=f if and only if f is closed, convex (with proof).
  • optimality conditions of simple optimization problems
  • Lecture 9 Tues. Oct. 13 Fenchel-Legendre conjugate/duality;
  • Fenchel Conjugate f* Properties: relation to affine functions; f* is closed and convex; when is f* proper and when is the domain of f* nonempty; f majorizes g implies g* majorizes f*; Fenchel-Young inequality with equality relationship to subdifferential.
  • support, positively homogeneous, sublinear, subadditive functions.
  • Sf is the set supported by f
  • Lecture 8 Thurs. Oct. 8 Fenchel-Legendre transform; conjugate/duality;
  • Summary of Notation and Basic Results
  • FYI: symbolic Fenchel conjugation/convex analysis maple packages
  • Lecture 7 Tues. Oct. 6 Homework 2, with Supplementary Problems; Fenchel-Legendre conjugate/duality;
  • f is a closed convex function (iff f is the sup of all majorized affine functions)
  • conjugate of a function, f*
  • Lecture 6 Thurs. Oct. 1 Applications of (Fenchel/conjugate) duality;
  • What shape is your conjugate? A survey of computational convex analysis and its applications, MR2496900, by Lucet, Yves, SIAM J. Optim. 20 (2009), no. 1, 216--250.
  • basic hyperplane separation
  • So, polar of a set and its properties
  • Lecture 5 Tues. Sept. 29 CVX outline, examples; Convex Hulls and Epigraphs
  • (CVX outline/examples)
  • compositions of functions that yield convexity
  • convex combinations, convex hulls of sets and functions
  • Lecture 4 Thurs. Sept. 24 Properties of Convex Sets and Convex Functions
  • sublevel sets, coercive functions, attainment of minimization problems
  • quasi-convex functions, indicator function
  • operations that preserve convexity (for convex sets and functions)
  • Lecture 3 Tues. Sept. 22 basic concepts of Euclidean spaces;
  • Supplementary Problems Homework 1 definition of domain added; GPs discussed; difference between Cartesian products and Direct sums;
  • basic concepts of Euclidean spaces; norms, open sets, closed sets, relative interior, affine manifolds, affine hull
  • Lecture 2 Thurs. Sept. 17 Homework 1, with Supplementary Problems; Convex Optimization (CO) Problems; Euclidean (vector) spaces
  • video lectures at Stanford 1; video lectures at Stanford 2;
  • Convex Optimization (CO) problems: LPs, SDPs, GPs (and info).
  • basic concepts of Euclidean spaces; constructing Euclidean spaces, e.g. using e.g. Cartesian products; norms, open sets, closed sets
  • Lecture 1 Tues. Sept. 15 Introduction/Administrivia; texts and supplementary references; CVX software (examples); Basic properties ( convex functions and convex sets)
  • "The great watershed in optimization is not between linearity and nonlinearity, but convexity and nonconvexity." ( Rockafellar, 1993.)
  • NEOS Wiki and the Optimization Tree; (graphic)
  • References: on reserve text is Convex Analysis and Nonlinear Optimization, by Borwein & Lewis.
    on reserve supplementary reference is Convex Optimization Theory, by D.P. Bertsekas.
    CVX, Matlab Software for Disciplined Convex Programming (download/install/example); using the online book Convex Optimization, by Boyd & Vandenberghe.
  • Lecture covered: convex functions: affine, exponential, entropy, quadratic, max, norms; convex sets: polyhedral, ellipsoids, cones