Mathematical Optimization
- Objective function:
- feasible set (eg, "constraints"):
- decision variables:
Abstract problem
- find such that is minimal, eg,
Gradients wanted
Assume the objective is differentiable on the nonempty interior of the feasible set
- measures the objective's sensitivity to feasible perturbations
- usually sufficient to devise tractable and implementable algorithms
Example: linear models
- least-squares approximation: minimizes
- least absolute-sum approximation: no closed-form solution for minimizing
Example: Scheduling
Minimize number nurses needed to meet weekly staffing demands
Constraints
- each nurse works 5 straight days with 2 days off
- nurses required on nights
First attempt
- nurses work on night
- minimize subject to with
- doesn't respect days off constraints
Scheduling: second attempt
let be number of nurses starting their 5-day shift on day :
- note the constraint structure. This is almost always true of practical LPs
- we may want to restrict to be integer. That's a much harder problem!
Coursework and evaluation
- 8 homework assignments (30%)
- programming and mathematical deriviations
- typeset submissions, correctness, and writing quality graded
- midterm exam (30%):
️ and
, short mathematical problems
- final exam (40%): multiple choice
Programming in Julia
- common programming languages in optimization: Python, Matlab, R; C++
- we'll use Julia only
- Matlab-like syntax, but free and fast
- lots of tutorials available
- Pluto
or Jupyter or ️notebooks highly recommended for assignments
Assignments
- work alone or collaborate in pairs
- hand in your own assignment and list collaborators
- 3 late days allowed (no permission required)
- but no more than 2 late days for a particular assignment
- no solutions posted online
- come to office hours to see solutions
- submit solutions to Crowdmark
Homework 1
- no late days, no collaborators
- hints at required background
- due next week
Resources
- see the course home page for schedule
- announcements and discussions on Piazza
- TA and instructor office hours start week 2
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