Questions tagged [quadratic-programming]

Questions on quadratic programming, the optimization of a quadratic objective function subject to affine constraints.

Quadratic Programming (QP) is a special case of where a quadratic function (called the objective function) of one or several variables is optimised subject to only affine constraints. Compared to (LP), only the objective function is different.

For $n$ variables and $m$ constraints, the objective is find an $n\times1$ vector $\bf x$ under the following conditions. \begin{align}\min\quad&\frac12{\bf x}^\top Q{\bf x}+{\bf c}^\top{\bf x}\\\text{s.t.}\quad&A{\bf x}\preceq{\bf b}\end{align} where, in the real numbers,

  • $\bf c$ is an $n\times1$ vector

  • $\bf b$ is an $m\times1$ vector

  • $Q$ is an $n\times n$ symmetric matrix

  • $A$ is an $m\times n$ matrix.

Common methods to solve them include the augmented Lagrangian and conjugate gradients.

Reference: Wikipedia - Quadratic Programming

776 questions
2
votes
1 answer

Re-allocating cells in rows in columns to equal given row and column sums

Suppose I have a matrix which looks like: $$ \left[\begin{array}{cccc} a_{11} & a_{12} & ... & a_{1n}\\ a_{21}\\ .\\ a_{n1} & & & a_{nn} \end{array}\right] $$ where $a_{ij}$ denotes the value of $a$ in row $i$ and column $j.$ For each row $i,$ I…
ChinG
  • 133
  • 1
  • 16
2
votes
1 answer

Find my mistake: Solving quadratic programm by "brute force" triangularization

Do you know the feeling when you have proven something totally incredible? In fact, it is so incredible you do not believe it yourself. So you start looking for your mistake, for the one, small logical flaw that turns all your believes upside down.…
Thilo
  • 255
2
votes
0 answers

Quadratic programming

For a research project I am interested in minimizing $x^TQx$ under the constraints $Qx \le b$, where $Q$ is a positive definite matrix and $b$ is a vector of negative elements. I have solved this with the Gurobi Solver, but as the matrix $Q$ is not…
1
vote
1 answer

Solving Quadratic Optimization problems without using Lagrange Multipliers

I am having trouble understanding min/max problems in Linear Algebra. I am normally used to solving these types of problems using some form of calculus. The question I am stuck on is minimizing: $$b^{T}x + \frac{1}{2}x^{T}x$$ subject to $$Ax = 0$$ I…
1
vote
1 answer

Quadratic program with equality and inequality constraints

I am trying to get the standard form of a quadratic program. The general form is as follows I don't understand how to get the matrix $a$ (for the coefficients of the inequality constraints) of the following specific problem: Please can anyone…
Rohail
  • 13
1
vote
0 answers

Algorithm and solver for large, dense, positive-semidefinite integer QP

I am interested in the solutions of a very large quadratic programming (QP) problem \begin{align} \min_{x \in \mathbb{R}^n} & x^T Q x\\ \mathrm{subject\ to} & A x = b\\ & x \in \{0,1\}^n \end{align} where $n=10^7$, $Q$ is a dense,…
1
vote
0 answers

Complexity of solving quadratic programming (QP) using ADMM

I am trying to analysis the time complexity of quadratic programming problem, using alternating direction method of multipliers. Anyone could give me a help?
0
votes
2 answers

Inverse quadratic optimization with linear equality constraints

considering following quadratic optimization problem with linear equality constraints \begin{equation} \begin{aligned} \max_w~& r^\top w - \frac{1}{2}w^\top Q w \\ \mathrm{s.t.}& \sum w = 1 \end{aligned} \end{equation} By given $r\in\Re^{N\times 1}$…
0
votes
0 answers

Is this a quadratic programming problem?

I have $N$ unknown 2D points ${\bf x} = (x,y)$ and I want to minimize: $f({\bf x}) = \sum_{i=0}^{N-1}{(||x_{i+1} - x_i||_2 - c_i)^2}$ where c are $N-1$ known scalars. What is the simplest form that I can use to solve this? I was thinking to try to…
Babis
  • 517
  • 1
  • 4
  • 10
0
votes
2 answers

Does this special case of convex quadratic programming have a partially-unique solution?

I know that a strictly convex quadratic programming problem has a unique solution, but I'm curious about the following situation: If $Q$ is positive definite, does the following problem: $$\min\limits_{x\in\mathbb{R}^n,y\in\mathbb{R}^m…
AlephZero
  • 750
0
votes
1 answer

Quadratic Program subproblem, what is the difference between $d$ and $d_k$?

What is the difference between $d$ and $d_k$? I have the explanation: Quadratic Program subproblem formulated as \ \ \begin{equation*} \begin{aligned} & \underset{d}{\text{minimize}} & & \frac{1}{2} d^T H_k d+\nabla f(x_k)^T d \\ & \text{subject…
S.n
  • 145
0
votes
1 answer

Given $f(x)=x^3$, prove if f is convex then any point $\bar{x}$ that satisfies $∇f(\bar{x})'\bar{x} = 0$ is a global minimum

I was given a question to apply the following corollary to the function $f(x)=x^3$ where $f: \mathbb{R}^1 \rightarrow \mathbb{R}^1$ and S is the set of nonnegative numbers $\{ x \mid x \geq 0 \}$. The corollary is: Suppose the feasible region is…
Nikitau
  • 1,353
0
votes
0 answers

Linearization a quadratiqe programming

I have programming problem with multiplication on its variables as $x_i x_j$. I introduced a substitution as $w_{ij}=x_i x_j$. But I cant show the relation between the results of the first and the second problems.
0
votes
1 answer

Why in quadratic programming is particularly simple when there are only equality constraints; specifically, the problem is linear

I found in wikipedia that... Quadratic programming is particularly simple when there are only equality constraints; specifically, the problem is linear font: Quadratic Programming What I can't understand is why. I didn't find any reference about…
0
votes
1 answer

SVM and quadratic programming

I wonder if the SVM optimization problem minimize $||w||^2$ with the contraints $y_i(w^\intercal x_i+b)\ge 1$ could be formulated as a typical quadratic programming problem: $0.5\cdot z^\intercal Mz$ with $Az\leq d$ and setting z to the vector…
1
2