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

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Constraints for LP [on hold]

Im fairly new to mathematica and I'm writing a minimization problem with constraints: ...
-8
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0answers
38 views

i need generalized code for genetic algorithm(an optimization technique)? [on hold]

I'm working on GA coding to optimize the locators position in fixturing system to minimize the error in precision manufacturing.I need generalize code for GA (including random population ...
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3answers
83 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: ...
3
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1answer
135 views

Finding peaks of data

I want to find peaks in my data. My code in a reduced form so far: ...
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0answers
50 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 ...
3
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3answers
68 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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1answer
86 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 ...
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0answers
43 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 ...
1
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0answers
56 views

Optimizing orthogonal nonlinear regression code

I'm doing a simulation problem on the Langmuir adsorption model, where I need to obtain the model parameters from simulated data using the orthogonal nonlinear least-squares regression method. Here is ...
4
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1answer
68 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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0answers
42 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
25 views

Using ForAll in Maximize to define a bunch of conditions

I'm trying to do something very straight forward. The following maximization works: ...
1
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1answer
46 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 ...
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1answer
66 views
2
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1answer
68 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: ...
2
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1answer
100 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: ...
2
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1answer
44 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 ...
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1answer
137 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 ...
3
votes
1answer
94 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 ...
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0answers
23 views

Timing of an Evaluation is not correctly displayed

From: http://reference.wolfram.com/language/howto/DisplayTheTimingOfAnEvaluationInANotebookWindow.html I ran a process that took about two minutes to finish. But the time recorded is only 0.18 ...
3
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0answers
59 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 that uses NonLinearModelFit with NMinimize as the method to do ...
3
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1answer
65 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 ...
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0answers
50 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: ...
1
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2answers
101 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 ...
0
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1answer
27 views

Plotting Minimize output for a range of constraint values

I want to plot the minimum of a function returned by Minimize over a range of constraint values. ...
1
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1answer
38 views

FindMinimum function does not produce minimum from near point

Using my simple program and I would like to find such matrix elements that minimize difference of their eigenvalues. ...
4
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1answer
52 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 ...
5
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1answer
107 views

Easy FindMaximum returns a wrong answer

FindMaximum in region is a new function in mma10,but when I tried the following example: ...
4
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3answers
144 views

How to fit parameters in a system of coupled differential equations

Problem description: I'm studying a chemical reaction that can be modeled by a system of coupled differential equations, and I want to use measured data to determine the parameters that appear in the ...
0
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1answer
91 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 ...
0
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0answers
20 views

Trouble with Minimize function

I'm trying to do my own curve fitting, by specifying a model, an error function, and minimizing it for some data. I realize I could just use FindFit, but I would like to do it this way just for fun. ...
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1answer
102 views

Implementing the Golden Section Rule

I am attempting to write a code which brackets the minimum of a unimodal function, using the Golden Section Method Below. I am have serious issues debugging my program though, any help will be ...
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42 views
0
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0answers
41 views

Solving Lagrangian (4 vars to solve for)

I'm a bit new to Mathematica, but here's what I've got: ...
3
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1answer
190 views

How to draw a tropical surface?

By definition, a tropical surface in $\mathbb R^3$ is the set of points $(x,y,z)$ where the maximum $f=max(f_1,f_2,\dots,f_n)$ is attained at least twice, here $f_i$ stand for some linear functions of ...
1
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1answer
79 views

Complicated equation solving

I want to find the maximum point or optimal value $y$ of Rx1[y_, a_, b_]. ...
6
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2answers
68 views

Maximise output issue

When I execute the following command, I get a numerical output as follows: ...
0
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1answer
34 views

Minimizing a function which involves Maximize [duplicate]

I have a mathematical function: $f = \frac{c^3}{2 a (k T)^3} \sqrt{\frac{\pi u v w}{2 b}} \exp \left[ - \frac{c}{k T} \sqrt{\frac{x^2+y^2}{a}+\frac{z^2}{b}} + \frac{1}{2} \left( \frac{x^2}{u} + ...
0
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1answer
56 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
20 views

NMinimize using NIntegrate functions

I'm looking for a minimization problem. I have a numerical function which is defined through a numerical intregation, which, in turn, have two parameters. The numerical integration is a very demanding ...
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0answers
105 views

How can I speed up this NM optimization? Most delay seems to be due to long analytic expression

I am struggling with computational speed of a NelderMead optimization. Nevertheless my impression is that I lose lots of speed not only due to the NM optimization itself but rather to for instance ...
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1answer
67 views

Looping within linear programming

I am trying to do some network programming around optimization. Here is a reduced sample: ...
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0answers
40 views

imaginary part in optimization problems

I have some trouble with an optimization problem. The constraints are always real, but in the first place there are also complex parts in the expression (which all sum up to 0). The problem now is ...
1
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0answers
66 views

Imposing constraints to NMinimize/NMaximize leads to wrong function values

I wrote a function that uses NMaximize to find certain parameters (using NelderMead simplex algorithm). My objective functional $J({x_i})$ is real-valued and its ...
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0answers
33 views

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
59 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
40 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 ...
0
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0answers
9 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
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2answers
140 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] ...
1
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2answers
139 views

Problems finding intersection points between line and generic function

I'm trying to find Intersection points between a line, which is given by 2 points, and a generic function (I want it to be able to handle polynomial functions, circles/ovals, lines and all ...