Questions tagged [nonlinear-optimization]

A non-linear optimization problem includes an objective function (to be minimized or maximized) and some number of equality and/or inequality constraints where the objective or some of the constraints are non-linear. Use this tag for questions related to the theory of solving such problems or for trying to solve particular problems.

A non-linear optimization problem includes an objective function (to be minimized or maximized) and some number of equality and/or inequality constraints where the objective or some of the constraints are non-linear. Usually, non-linear optimization problems are much harder to solve than linear ones.

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Non-linear optimization: Levenberg-Marquardt gives different results using different forms of the same function

Background: I'm using non-linear least squares to solve indoor trilateration problem using BLE (bluetooth low energy) beacons. My starting point is this: https://nrr.mit.edu/sites/default/files/documents/Lab_11_Localization.html B part of the…
bartfer
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Formulate the Langrangian function of a non-linear optimization problem and solve it for $y\geq0$

Consider the (non-linear) optimization problem ($P$) $$max \quad3x_1 + 4x_2$$ $$s.t. \quad x_1^2 + x_2^2 \leq 25$$ $$ \quad x_1,x_2 \geq 0$$ Formulate the Lagrangian function $\varTheta(y)$ and solve it for fixed $y>0$ This is the function that I…
dreamer
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Linearizing a program with multinomial logit in the objective

I have a nonlinear problem as follows: $$ min \sum_{k=1}^{K}|y_k - \sum_{i=1}^{N} \frac{e^{x_{k}^{i}}}{\sum_{j=1}^{K} e^{x^{i}_{j}}}| \\ st \quad x^i_{j} \ge 0$$ Essentially, there are $k$ buckets with a desired value of $y_k$ for each. There are…
Alex
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Partial alternating minimization for solving generalized consensus optimization

I'm trying to solve to the following generalized consensus optimization problem, which is a particular kind of nonlinear nonconvex problem: $$\begin{equation} \tag{P} X^*=\underset{x_i \in \mathcal{X}_i,~ \forall i \in \{0,1,\dots,N\} \\ y \in…
duburcqa
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Standard Wolfe condition for matrices

I have an optimization problem that I want to solve with conjugate gradient descent method. Definition is as follows: $$\operatorname{argmin} f(X)$$ Where $$f(X)=\sum_{s=1}^{T} \left \| F_sX(:,s)-Y(:,s)))\right \|_{2}$$ I want to obtain the…
strahd
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Minimize the sum of exponentially increasing values with a product constraint

I would like to minimize $$\sum^N_i \sqrt[2^i]{x_i} = x_0 + \sqrt{x_1} + \sqrt[4]{x_2} + \cdots$$ subject to the constraints $$1 = \prod^N_i x_i = x_0x_1x_2\cdots $$ and $$x_i \in (0, 1]$$ Is this even a well defined problem? I am a bit out of my…
Daniel King
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Why only Nelder-Mead simplex method?

For constructing simplex, we can use any combination of contraction, shrink, reflection and expansion. So why we use the particular order that is being described in Nelder-Mead simplex method?
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Non-linear least squares, problem with shifts

There is a set of coordinates $P=\{P_i\}$. $P_i=[x_i,y_i]$ and a set of coordinates $Q=\{Q_i\}$, $Q_i=[X_i, Y_i]$, where $Q_i$ coordinates are given by the following non-linear functions $$X = f (a_1, a_2, a_3, ..., a_7)$$ $$Y = g (a_1, a_2, a_3,…
justik
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Solution to Fermat Point optimization problem.

There are 3 points in a plane $(x_1,y_1)$,$(x_2,y_2)$,$(x_3,y_3)$. I am trying to find a solution to the unconstrained minimization problem which is the point $(a,b)$ of least distance between the 3. $\min F(a,b) = \sum_{i=1}^3…
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A non-linear maximisation

We know that $x+y=3$ where x and y are positive real numbers. How can one find the maximum value of $x^2y$? Is it $4,3\sqrt{2}, 9/4$ or $2$?
Basil R
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Find a direction that minimizes the function

Let's say I have a function $f:\mathbb{R^n} \rightarrow \mathbb{R}, f \in C^2 $ and $x^k \in \mathbb{R^n}$ such that $\nabla f(x^k) = 0 $, but $\nabla ^2f(x^k) $ is not positive semi-definite, can I find a direction $d$ such that a point $x^{k+1} =…
Rael
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Significance of Whitney's theorem

Consider the nonlinear optimization problem below: $$p^* := \min f(x)$$ $$\textrm{s.t. }\ g_i (x) \leq 0,\ \forall i = 1,...,m$$ $$h_j (x) = 0,\ \forall j = 1,..., p$$ $$x \in D$$ where $f, g_i, h_j : D \rightarrow R, i = 1,..., m, j = 1,...,p$ are…
Teodorism
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how to choose Marquardt parameter when the variable have different scale

I knew the the Marquardt parameter could switch the different edition between Gauss-Newton and steepest descent method , It add a lambda at the diagonal of Hessian matrix but what if the jacobi of different variable have different order of…
Mr.Guo
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Inequality constrained problem with the number of binding constraints equal to the number of choice variables

I am trying to solve the problem below using basically Theorem 2 that is presented in these notes. It describes the usual method of solving the problem of static optimization when you have equality and inequality constraints. The basic idea is to…
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Efficient conjugate gradient method against BFGS for nonlinear optimization

I am trying to optimize an unconstrained non-convex optimization problem. I know that, in general, BFGS takes fewer iterations than conjugate gradient method but consumes more memory (and hence sometimes more computational time). However, I…