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

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Passing complicated functions to NMinimize [duplicate]

I am using NMinimize to do a minimization of sum of squares. I have a module based on the following code ...
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0answers
100 views

Minimizing/maximizing function and selected parameters simultaneously

I have a function over several variables which I would like to minimize while maximizing (or minimizing) at least one other variable subordinate to the global function minimum. As a trivial ...
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0answers
42 views

How to add a positive definiteness of a unsymmetric matrix as a constraint to a Findminimum problem

The problem is I have a function which has 33 variables, and which to minimize it in a given set of contraints. I have also a matrix consisting of these 33 variables. The condition is that this matrix ...
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0answers
10 views

Add positive definite matrix constraint to an optimization problem [duplicate]

The problem is I have a function which has 33 variables, and which to minimize it in a given set of contraints. I have also a matrix consisting of these 33 variables. The condition is that this matrix ...
1
vote
2answers
208 views

Minimizing the largest difference between two functions

I have two functions defined on the same domain, $f(x)$ and $g(x)$ where $x$ is in $(0,1)$: f[x_] := (-1 + x) Log[1 - x] - x Log[x] g[x_] := Log[1 + 2 (-1 + x) x] ...
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2answers
66 views

Vector optimization with vector length as a free variable

I'm trying to solve the following problem: For a vector $v$ of length $c$, $\min \frac{\sum v[i]^4}{(\sum v[i]^2)^2}$ subject to $\sum v[i] = N$. I can solve this numerically for a given $c$ using ...
1
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1answer
87 views

Optimizing matrix inequalities over trace

I need to solve the following problem. Given $n \times n$ Hermitian matrices $A\geq 0$ and $B_1, ~ B_2$ (need not be positive semidefinite), with $Tr(AB_1)<0~,Tr(AB_2)<0$ construct a ...
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0answers
34 views

FindMaximum slow for fixed parameters

I hope my problem can be solved by just showing you this tiny part of my code which does not run on its own. I have an optimization problem and want these functions to work on various data sets. ...
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0answers
47 views

Parallelize: No speed-up when using with FindMaximum

I have developed a program to compute the maximum value of an specific function multiple times, with different parameter values each time. I've been using the ...
1
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1answer
64 views

Precision of starting values in FindMinimum [closed]

I am currently working on an optimization of chemical kinetic model. Starting points for FindMinimum are defined as: ...
7
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3answers
742 views

Built-ins for discrete ArgMax or ArgMin?

Wondering whether there are discrete versions of ArgMax / ArgMin, that is, something that will find the part of an expression at ...
2
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2answers
106 views

Only one root at specific interval

I need a help to find k here: $f(x)=-k^x + x^2$ It is not too simple. I have interest to find the single value of "k" where, inside interval {x,2,3}, the function have only one value to x when f(x) ...
24
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4answers
6k views

Finding Local Minima / Maxima in Noisy Data

I'm trying to find local minima / maxima in noisy data, consisting of data values taken at certain time intervals. Ideally, the function should take a pair of lists (one containing time values and one ...
0
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0answers
67 views

Mathematica global optimization add ons

Can somebody tell me the major differences between Global Optimization add on, MathOptimizer Professional, and NMinimize which does global optimization in ...
0
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0answers
109 views

How to find Multiple Maxima/Minima

I am trying to solve a problem that requires finding multiple maxima of a numerical function. So the function generates some numbers that are coming out of an experiment. I tried using NMaximize or ...
3
votes
2answers
118 views

Finding large Collatz Sequences, trying to improve speed

Background: I am already very much in love with Mathematica but I am also a novice. So far I have only gathered experience in procedural programming in Python. Generally speaking I am trying to ...
2
votes
1answer
100 views

Simple-looking Minimize takes for ever

Consider the following: Minimize[{(ξ - x)^2 + (η - y)^2, a ξ + b η == c}, {ξ, η}, Reals] After asking Mathematica to do this yesterday afternoon and forgetting ...
2
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1answer
142 views

How to implement the dual Lagrange?

I have seen in the Pang book of data mining the following example: ...
0
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1answer
67 views

Optimizing complex functions

I am trying to optimize a function containing complex numbers, however I keep running into errors. Consider the simple optimization problem: ...
0
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1answer
92 views

Incorporate error bars to best-fit curve [closed]

I have managed to get mathematica to perform a best fit curve. However, I wish to add error bar to the curve, how do I do so?
0
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0answers
17 views

NMinimize as objective function of NMinimize [duplicate]

Let f[x_,z_]:=... g[x_,z_]:=... fully numerical apart for x and z. Then, I want to find z by minimizing f^2 for given x. Then, I want to find x that maximize g for z in the first step (which is a ...
1
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2answers
184 views

How do I disorder a list in Mathematica?

Given a list like this (the original list is much longer), how I can get a completely unordered list and save it in plain text? I change the file names (names at random), using a length of 5 digits, ...
0
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0answers
47 views

Some of System words in Mathematica 10 doesn't show right

Does anyone have any idea about why this happens and how to solve it? thanks.
2
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0answers
41 views

Where can I find detailed information about the SystemOptions?

I'm looking to optimize my Mathematica script, and I'm willing to go spelunking with low-level system options. The problem is that I've been looking in the Mathematica documentation, but there ...
4
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1answer
97 views

FindMinimum's WorkingPrecision behaviour

I discovered the following behaviour when using FindMinimum for constrained optimization: ...
0
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0answers
35 views

Convex problem solution

I have the following optimisation problem, where $l,m,n$ are positive. It is a convex problem. I need to find the optimum under a budget constraint. ...
0
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0answers
180 views

Is there a way to give Mathematica extra memory?

I am running Mathematica 10 (Student Edition) on Mac OS X 10.7.5 on an old Mac Pro. I have lots of extra RAM that the system isn't touching, and I would like to give some of it to Mathematica in the ...
5
votes
1answer
150 views

Slow-down encountered when using NMinimize with a compiled function

I'm minimizing a large function. Evaluating the function is very slow symbolically but using Compile I can get ~100x speed-up on this step. However, despite this, the NMinimize process is only ...
0
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0answers
99 views

How to properly pass function as argument here? --> NMinimize & NIntegrate involved

I had a problem of a similar kind here which was solved. Now after changing a few things in my problem setting I am suffering from the following problem. Let me first introduce methods/functions that ...
1
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1answer
91 views

The problem (time) caused by ?NumericQ

In here, I asked a related (similar) question. Using ?NumericQ seems have slowed down the entire calculation. But I now have a more serious problem: ...
0
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0answers
61 views

Fit a complicated function to a constant with NonlinearModelFit

I wish to fit a complicated parametric function (logder, with lambda parameters) to a constant (L) in order to minimize its dependence with the variable k in a given interval. To do that, I use a ...
6
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1answer
284 views

How trustworthy is NMaximize?

Suppose I solve a constrained optimisation problem using NMaximize. How confident can I be of the accuracy of the result? For concreteness, suppose that F,G are ...
1
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1answer
51 views

Getting result from Maximize

I'm trying to get maximization result from Maximize function to use it in later calculations. At the moment I use the following code: ...
0
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0answers
34 views

Variables input generation for Minimization in High dimensional space

I'm currently doing optimization in a high dimensional space. I was thinking of giving FindMinimum (or NMinimize not certain ...
0
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0answers
31 views

How to evaluate NMinimize inside a function

I want to define a function that returns a sum of differences of some points to a given function. To obtain these differences I would like to use NMinimize, but if I implement that straightforwardly, ...
0
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0answers
35 views

Tricks to speeding up optimisation of a function involving a heavy integration

This is the code, and energycoeffs[] is the function that takes in a dxd matrix and spits out a scalar value. ...
1
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2answers
172 views

Problem with FindMinimum

I am struggling with a problem on fitting a function to my data using FindMinimum. The problem is related to small angle x-ray scattering and my approach is the following: I define the electron ...
1
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1answer
125 views

Using FindMinimum with matrix input

I define the following function which spits out a number S when I feed it a dxd square matrix: ...
1
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0answers
114 views

NMaximize with matrix input

I defined function f[x_, fixed_] := {...}. Here x is an $M\times N$ matrix. I want to maximize $f$ with respect to $x$. I have ...
0
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0answers
80 views

Problem with the laplace transform

I am trying to write a program in mathematica to solve green's functions, like the following. They come up all the time in Quantum Field Theory. I have learned, student's can sometimes see it better ...
0
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0answers
25 views

Iterating a model with 2nd order difference equations using Manipulate [duplicate]

I have a model including first and second order difference equations. It works for the case of first difference equation, which is below: ...
1
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2answers
105 views

optimization of CountourPlot with NIntegrate

I have to use ContourPlot with a complicated function depending on 2 parametrs (that I cannot report here) that contains numerical integrations. Here is a simple ...
4
votes
2answers
99 views

NMinimize in one-dimensional Interval

An Interval should be a one-dimensional region, so a region. I tried to minimize a function over an interval, e.g.: ...
1
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0answers
118 views

How to plot feasible objective space of a Generic Multiobjective Optimization problem?

As you know, a generic Multiobjective optimization problem can be stated as follows: $min{\space}F(\bf{X})=[f_1(x),...,f_n(x)]$ $h_k(x)=0{\space\space\space} k=1,...,n_e$ ...
20
votes
1answer
611 views

Convex optimization

I am playing with some Compressed Sensing (think single pixel camera) applications and would like to have a Mathematica equivalent of a Matlab package call Convex Optimization (CVX). Specifically, I ...
4
votes
0answers
132 views

Packages for Semidefinite programming

This question has already been asked here. I am not sure, whether I should have asked this question as a comment of an old question or in the general programming forum of stackexchange. Moderators ...
-1
votes
1answer
78 views

Black Ovals appeared in my Mathematica notebook [duplicate]

I copied and pasted something from another Mathematic notebook and started getting the same black ovals seen in this question: Colored marks appearing in notebook input text? The suggestion to turn ...
5
votes
0answers
181 views

How to determine reason for kernel crash? -> Nelder Mead optimisation

I am making use of the Nelder Mead algorithm inside Mathematica's NMaximize to find a parameter set by solving the Schrodinger equation for a given system. (see ...