
Explore one-dimensional unconstrained optimization and constraint handling. Learn equality and inequality constraints and methods like golden search, Newton's method, and the garage multiplier method for constrained problems.
Apply Newton's method to optimization by solving f'(x)=0 and updating x via x_new = x_old - G(x)/G'(x), where G is the derivative of f, noting initial guesses influence extrema.
Explore the secant method for optimization by replacing derivatives and Newton's method with finite difference approximations, using central difference formulas derived from Taylor expansions with delta x squared error.
Examine a one-dimensional optimization problem using Newton's method and a finite-difference alternative. Starting from x=1, it converges to 1.427, locating a local maximum via f'' negative, with plotting and code.
Explore multi-dimensional unconstrained optimization using contour plots for two variables, x and y, locating maxima and minima, and comparing non gradient methods with gradient approaches.
Develop background for gradient methods by using the chain rule and gradient operator to find directional derivatives, and apply an example at (1,1) to locate the steepest direction.
Explains maximizing f(x,y)=100-3x^2-y^2 by a line search along the steepest descent, deriving g(h) and iterating toward (0,0), with a preview of finite-difference derivatives and Fortran-based Newton optimization.
Extend Newton's method to two dimensions by solving a system of nonlinear equations with a Taylor series linearization, iteratively updating x and y until convergence.
Learn the Lagrange multiplier method for equality constraints, convert inequalities to equalities, form the Lagrange expression Z with lambda multipliers, and solve the resulting system via a Newton-like method.
Minimize a cylinder's surface area under a fixed volume using a Lagrange multiplier; derive a three-equation system and solve with extended Newton's method, illustrated on a 55-gallon drum.
Solve a constrained optimization problem with Fortran, derive a three-by-three system, analyze a Lagrange multiplier, perform a volume check, and compare Gauss elimination with fixed-point iteration.
Use fixed-point iteration to solve a system of nonlinear equations. This is an alternative to the extended Newton's method we have used previously in this section.
Explore fixed-point iteration with concise Fortran code and a 25-iteration loop using a relaxation factor. See how generic solvers apply beyond optimization, with easy coding but potentially slow convergence.
Code to find Max/Min of f(x)=2*Sin(x)-x^2/10 using Newton's method
and Secant method alternative.
OPTIMIZE LENGTH OF BEAM TO MINIMIZE A FORCE
Code to solve minimize x^2 + y^2 subject to x+y=2 and 1<=y<=2 using Lagrange Multiplier method.
Note: Application3.f90 code replaced on 1/9/2023 due to bug fix found when converting to Python version.
Program to minimize cost of building a box of fixed volume given the cost of materials using Lagrange multiplier approach.
Golden Search Optimization Method (using only 1 functional evaluation per iteration) for Box Problem in Application 4 using a reduced number of unknowns (by building constraints into cost equation).
This course provides a basic introduction to optimization methods for science and engineering students which is often taught as part of an undergraduate-level numerical methods class. The material covered here is at that level, and includes:
· Newton and Secant methods for one dimensional unconstrained problems.
· Golden search bracketed method for one-dimensional unconstrained problems.
· Univariate search for multi-dimensional unconstrained problems.
· Steepest Ascent Method for multi-dimensional unconstrained problems.
· Newton’s Method for a multi-dimensional unconstrained problem.
· Lagrange multiplier method for multi-dimensional equality constraint problems.
· Lagrange multiplier method for multi-dimensional inequality constraint problems.
· Example problems using the above methods.
Course notes are available for download. Computer codes used to solve these problems, written in both Fortran95 and Python, are also available for download and may be easily modified for your own use.
The material presented is suitable for students in a sophomore or junior level science, technology, engineering and/or mathematics numerical methods class. A background in calculus is necessary, as is the ability to program in a computer language such as Fortran90, C, C++, Python, MatLab, etc.
x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x