Questions on the optimization functions of Mathematica such as FindMinimum/FindMaximum, Minimize/Maximize, NMinimize/NMaximize, etc.

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Finding the global extrema of a surface? [closed]

I am trying to figure out how to find the global extrema of the function surface shown below and can't seem to get answers that make any sense. I am using the FindMinimum and FindMaximum functions ...
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1answer
232 views

Fibonacci Line Search Method

I am attempting to write a code to find to bracket the minimum of a function using the Fibonacci Line Search Method, I believe my code is well written but I am not ...
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0answers
136 views

How to optimize a cost function which involve the solution of a ODE system using the NMinmize?

I have created a cost function, the value of which depends on the solution of a ODE (ordinary differential equation). The parameters of the ODE are not determined, and my goal is to determine them ...
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0answers
100 views

Fun/Frustration With Coding Coding Theory

I have code following from this post: http://math.stackexchange.com/questions/1317722/fun-frustration-with-coding-coding-theory I think I am done with the code, but now I face a single problem. The ...
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1answer
82 views

Find a minimum value which satisfies an equation

I have to find a minimum value of "a" which makes x=-a+b+c, y=-a+b+c^2 positive where a>1, 0 ...
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1answer
83 views

Problem in minimizing expression

I am trying to implement bootstrapping (https://en.wikipedia.org/wiki/Bootstrapping_(finance)) of CDS curve. To implement it I am trying to minimize a series of expression. The minimum value of ...
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2answers
115 views

Finding Minimium Periapse Distance Between Spacecraft and Planet

I have the following simple model that simulates a spacecraft orbiting Mars. What I'm hoping to do is be able to find the periapse radius of the spacecraft as I did below, except instead of using ...
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2answers
176 views

FindMinimum and WhenEvent

Is there any way to incorporate WhenEvent[] into the FindMinimumfunction ? I'm currently trying to minimize an interpolating function with FindMinimum (since the origional function is to cumbersome ...
2
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1answer
209 views

NMaximize with Nelder-Mead method fails to convergence when tolerance set too high

Recently I have been working on a optimization problem for which I use NMaximize with Nelder-Mead method. In general, I have to check a lot of systems which are built automatically. I want to skip ...
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0answers
54 views

Sharp Ratio Maximization, Closed Forms

I am trying to get a closed form for the following first order conditions (n=4): Here's the nb-File. The code is as follows: ...
5
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0answers
169 views

Custom Methods for NMinimize/NonLinearModelFit

Is there a way to write custom methods for NonLinearModelFit or NMinimize? To give background, I currently have a batch of code ...
9
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2answers
298 views

Relaxation of Mass-Spring System with Pinned Masses

Problem Assume that four masses are connected to each other by springs while two of them are pinned down at their initial positions. Find the position of masses when system is at its minimum (...
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1answer
121 views

Both FindMinimum and NMinimize have trouble

I'm trying to minimize a function I wrote, in a not entirely elegant (but functional) way. As a side note, if you have advice on how to write this in a smarter way, that's also welcome. In any case, ...
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2answers
203 views

Reordering numerically calculated eigenvalues assuming smooth dependence on a parameter

As was discussed in a different question here on SE (link) if you compute eigenvalues numerically of a matrix which depends on a parameter y, the resulting plot of ...
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0answers
88 views

Symbolically Minimizing a Max function

I'm having a tough time with seemingly simple symbolic Minimization/Maximization in Mathematica. I would like to use the Maximize function to work on some unknown random variables and so use min/max ...
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1answer
126 views

Equation solution using minimization

I have an equation F[x,y]=0. I need to plot y as a function of x. Due to the properties of ...
5
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0answers
94 views

How to perform Bayesian optimization with Mathematica? [duplicate]

Does Mathematica have any Bayesian optimization methods for learning hyper-parameters? Practical Bayesian Optimization of Machine Learning Algorithms Jasper Snoek, Hugo Larochelle and Ryan P. ...
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0answers
256 views

Optimization method L-BFGS-B

I am comparing a result of optimization using R and Mathematica. Mathematica (NMaximize) has found a significantly better (global optimum) result then R (using L-...
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0answers
113 views

How can I calculate Lagrange multiplier and the critical points with Mathematica? [closed]

I have constraints and a function I want to know the critic points but is there a way that I can compute this method so that I can see results faster
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1answer
945 views

Finding peaks of data

I want to find peaks in my data. My code in a reduced form so far: ...
18
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3answers
4k views

How can I implement the method of Lagrange multipliers to find constrained extrema?

I want to form the function $h=f-\lambda_{1}g_{1}-\lambda_{2}g_{2}$ where $f$ is the function to optimize subject to the constraints $g_{1}=0$ and $g_{2}=0$ so that I can solve the first partial ...
8
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2answers
661 views

Is there any fast way to solve a quadratic matrix equation in Mathematica approximately?

Let the square nonsingular matrix $M$ is a given convergent matrix. What are the best scalar values for $\alpha$ and $\beta$ (in the real numbers domain), at which the following quadratic matrix ...
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3answers
245 views

Minimize method is not giving minimum. Why?

I was doing an optimization but facing a problem getting what exactly Minimize function do. I run the following code: ...
16
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2answers
578 views

Determining the default Method used in optimization and root-finding algorithms

Is it possible to extract the Method which is used in functions like NMinimize, FindRoot, <...
3
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3answers
127 views

Minimizing Multiple Functions

I'm trying to write a script that will minimize a given set of functions. The homework problem I've been given lists a set of dietary information, and I'm supposed to build the optimal salad based on ...
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0answers
69 views

Which method to use for finding maximum without actually computing optimization function explicitly?

I am new to Mathematica and I am currently working on an optimization problem. The optimization function that I have easy to calculate for some assignment of variable but it is very difficult to ...
2
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1answer
341 views

How to build a list of constraints for NMinimize

Let's say I have aset = {-1, 0, 2}. I would like to create a variable Var that takes values from that set, i.e. ...
4
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1answer
137 views

What is the status of the FindMinimum method “QuadraticProgramming”?

As a method option to FindMinimum "QuadraticProgramming" is still a valid option. It has the advantage of being significantly ...
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105 views

Constrained optimization and problem with complex numbers

I am trying to solve a constrained optimization problem with an implicitly defined function $\pi$. The problem is non linear and of high order, so I use numerical methods instead. The code I use is: <...
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0answers
129 views

Using NMinimize to solve the Multi Commodity Flow problem

I have the following optimization problem and I was hoping to solve it with NMinimize. Unfortunately, I don't get the desired result. I would like to get an optimal vector for $d_{e}$. This is how ...
2
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1answer
131 views

Maximizing the number of zero entries in a matrix

I have a matrix with a bunch of parameters in its entries, they all come in different combinations in different places of the matrix. I can post the matrix itself if requested, but I think what I mean ...
6
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1answer
534 views

Lagrange Multiplier

We are asked to maximize and minimize $f(x,y)=4xy$, given the constraint $4x^2+y^2=8$, using the Lagrange Multiplier method. First, I enter the functions f and g. ...
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2answers
268 views

Is it possible to monitor the sum of squared errors in a NonlinearModelFit or FindFit procedure during the process?

Since fitting procedures using NonlinearModelFit (or FindFit) sometimes take very long, I would like to monitor the sum of ...
3
votes
1answer
107 views

How can I change a lot of parameters to Real? [closed]

Because of some formulas with Conjugate in a notebook, I have to tell mathematica to change a lot of parameters to Real! I know that I can use Refine with Element or Assumptions: ...
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2answers
102 views

Does FindFit use symbolic differentiation?

Does FindFit use symbolic differentiation when optimizing by least squares a non-linear function?
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1answer
158 views

Minimization Nminimize nnum error

I have imported data (mat is the name, 1x100 dimensional vector)and written a likelihood function for normal distribution. ...
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0answers
41 views

Using ForAll in Maximize to define a bunch of conditions [closed]

I'm trying to do something very straight forward. The following maximization works: ...
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1answer
80 views

NMinimize error: Nearest::neard:

I have this function GuessError, here's a plot assuming a single variable x, Plot[GuessError[10^x, etc..], {x, 8, 12}] , being etc some more variables which are ...
2
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1answer
100 views

NMinimize works only if expression is pasted directly

Niminize works fine if I copy the minimized function directly by hands, but doesn't work if I try to do something like this: ...
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1answer
144 views

Why does it matter at what point I replace?

I need to find four orthogonal linear combinations of complicated functions, that vanish at four different points. I use (LK4 is defined below, but its shape should have nothing to do with my problem)...
2
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1answer
72 views

Application of Maximize: The cuboid constrained to the ellipsoid in $\mathbb{R}^3$

Since I am a student of Mathematics I enjoy to apply MMA to problems that I have a solid understanding in. The following would be such a problem: Maximize $f: \mathbb{R}^3 \to \mathbb{R}$ given by ...
3
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1answer
174 views

How to stop optimization (e.g. NMinimize) after reaching target value

Suppose we have some function f[x,y] that we want to optimize in way that we are only interested in values (x,y) that guarantee ...
4
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1answer
104 views

Why does EvaluationMonitor in FindMaximum only work for some regions?

This has come about after trying to understand what was going on with this question about FindMaximum and regions. My first thought in that scenario was to set-up <...
3
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1answer
87 views

Why minimization does not work with symbolic array as arguments

If I try to minimize with constraints a function of several variables, with Gamma regularized function involved in the constraints it seems to works, as shown below (this is just a dummy example ...
1
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2answers
122 views

Minimize the sum-of-squares errors for a system of ODEs

I'm trying to minimizing the sum of squared errors on a 2-equation system of ODEs and empirical data. I keep getting an error and I think the root of the problem is my invocation of ...
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0answers
120 views

Maximize and NMaximize don't work for my function

I defined the following function: d1[x_] := Min[Abs[FractionalPart[x]], 1 - Abs[FractionalPart[x]]] and tried to evaluate the following function: Maximize[{Min[d1[15*x],d1[12*x],d1[18*x]],...
4
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1answer
125 views

Possible bug / numerical issues with HypergeometricU — any suggestions for a fast workaround?

I've encountered some problematic behaviour with HypergeometricU. I have a probability distribution on the positive integers that takes the following form after ...