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

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2answers
85 views

Incorporating the minimum and maximum of the function in a Dynamic plot

I'm working on my project for class and it's supposed to be a graph that can take functions from the user and display it along with finding the max and min of the graph. But I just don't know how to ...
0
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0answers
36 views

3D Ploting in Mathematica Function is getting smeared [duplicate]

A = x^2 + y^2 + Sqrt[x^2 + y^2]; B = x^2 + y^2 - Sqrt[x^2 + y^2]; Plot3D[{B}, {x, -1.5, 1.5}, {y, -1.5, 1.5}] I want to remove this sky blue region from the ...
3
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1answer
106 views

Calculate the relationship between the duration of two oscillating functions

I am trying to quantitatively determine the relationship between the length of two oscillating functions. Meaning, what is the duration of the green spike in relation to the blue square? Does anyone ...
0
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0answers
52 views

NMinimize tries to find the fit to paramters which are not in the objective function

Consider the codes below: fun[x_] := (x - 4)^2 NMinimize[{fun[x]}, {x, y}] it returns: ...
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0answers
60 views
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0answers
81 views

Optimiazation 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 ...
0
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1answer
94 views

Optimizing a System of 5 Equations

I have a system of 5 equations that each define a parameter for a metal I-beam. The common variables are beam width (W), web thickness (Tw), and flange thickness (Tf). I would like to find the best ...
19
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2answers
803 views

Optimization with assumptions

I have the following problem, when I am trying to optimize function with pre-defined assumptions. I am using Mathematica 8 and I wrote the following simple code ...
5
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2answers
140 views

Test existence of a path from one side of a graph to another

I'm trying to determine how I can test if a path exists from one side of a graph to another as efficiently as possible. If I have the Lines given by: ...
1
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0answers
109 views

Mathematica + System Modeler or Matlab + Simulink [closed]

I want to learn control systems(Using Ogata Modern Control Systems Book) and I am not sure in which should I invest : Matlab+Simulink+Control systems = aprox 220 euro Mathematica + Workbench + ...
46
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4answers
10k views

How to find all the local minima/maxima in a range

I want to find : all local maxima in range all local minima in range From those points I can interpolate and combine functions upper and lower boundary. What I am really interested in, is the ...
5
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2answers
78 views

Optimization problems over the Integers

Should be an easy question. How can I define a function which gets only integers in a form that I can use to find max and min for instance? Example: Find the Max of the expression ...
0
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1answer
74 views
4
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2answers
406 views
0
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1answer
69 views

FindMinimum runs out of Memory

I have a function (its rather long, but does not matter) which when evaluated (1000s of times) runs fine. However, when I try to find its optimal parameters using ...
1
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1answer
41 views

Minimization problem in a subset of Complex matrices

I would like to minimize $||\mathbf{A} \rho -v||$ (where $\rho , v$ are fixed vectors) with respect to the matrix $\mathbf{A}$ elements, but with $\mathbf{A}$ in a subset of complex matrices (i.e. ...
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0answers
45 views

Transform NMinimze into LinearProgramming formulation

I have the following maximization problem that I currently try to solve with Minimize/NMinimize. Unfortunately, this kind of solution method takes really long for large systems of equations and ...
2
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1answer
81 views

Array in Sum in Minimize - error “Part specification x[1] is neither a machine-sized integer”

Help please M = 10; z = Array[x, M] {x[1], x[2], x[3], x[4], x[5], x[6], x[7], x[8], x[9], x[10]} ...
7
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4answers
318 views

Finding the point of minimum distance between two parametric functions

I have two functions re and rm, for which I computed the minimum distance between them. Now I would like to add a point at the ...
0
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1answer
284 views

Implementing Rayleigh criterion method for finding the resolution of an optical system

I want to use the Rayleigh criterion to find the resolution of an optical system. I have two functions f1 = Sinc[x]^2 and ...
1
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0answers
91 views

Is there any way to solve this convex-concave like optimization problem?

This is a bit of a non-standard way of asking a question perhaps but I couldnt even think of writing any code about the following optimization problem. I wonder if it could be at all solvable and if ...
3
votes
2answers
153 views

NMinimize/NMaximize is unable to generate initial points

Mathematica 10 generates a warning that it is unable to generate initial points for numerical optimization problems. I picked a particularly simple example. The problem goes away when ...
0
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1answer
116 views

Optimizing Chi-square distance between two distribution

I want to program the chi-square between two distribution Xu and Vu with length N. This function is defined as below: Xu and Vu are real and positive. ...
1
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0answers
66 views

Updating procedural fitting algorithm to more efficient style?

For some time now, I have used this procedural programming approach to fit data in my research that is too cumbersome for the built in Mathematica functions. (Although this simple example works fine ...
1
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1answer
109 views

Optimization in MMA for time resolved spectroscopy

I want to fit some spectroscopic data with a model. I detect the fluorescence of something over different wavelengths. The detection over each wavelength is one data set in time. The lifetimes of ...
0
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0answers
59 views

Using FindFit to return a list of possible best fits

Can I use some variant of FindFit that will return a list of the best fit and some worse fits, not just the best fit? This is for a function where the residual function can have several local ...
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0answers
60 views

Improve on timing of NMinimize

I got a little performance problem with the function NMinimize (it takes mathematica approximately 10 minutes to compute the results). Here i s my sample code: ...
5
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0answers
125 views

PenaltyFunction Option in NMinimize

I am curious if anybody has some experience in using the built-in Option "PenaltyFunction" in any of the numerical optimization functions like NMinimize. According to the documentation the user ...
0
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0answers
39 views

How to set the step in NMinimize

I want to fit multiple data sets with 104 variables. I use NMinimize to do that. I minimize the difference between data and my objective function. How can I tell ...
0
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0answers
31 views

Optimization of two functions under one common constraint

Is it possible to optimize two functions under one common constraint? So to find the common maximum? For example, Optimization of (* 1 *) x*y^2-x^2 (* 2 *) x*y ...
1
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1answer
76 views

Matlab's command counterpart in MMA

Matlab has a command that when is used in fminsearch shows the value of the function which we want to minimize and so gives a trend of values calculated for the ...
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0answers
53 views

Speed up numerical optimization (for plotting and solving)?

Briefly speaking, I want to plot a function PIfun[], which its value is based on numerical optimization using NMaximize. It ...
9
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4answers
288 views

How can I efficiently check if a graph is unit distance?

A unit distance graph is a graph that is embeddable in the plane so that every edge has length 1. ...
0
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2answers
60 views

A constraint to RandomReal for sum of numbers equal to arbitrary n

I want to generate some random numbers but respect a constraint. So I use RandomReal[{0,1},N,WorkingPrecision -> 2] I want to fix a constraint in order ...
0
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0answers
37 views

NMinimize outside the feasible region

I got the following minimization problem. I get a solution if I set constraints1 := L.x >= y; and eliminate constraint 2 from my set of constraints. So ...
1
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0answers
66 views

NMinimize: Problem with constraints + Simultaneous minimization possible?

Introduction Dear all, I am fairly new to Mathematica. Recently I am trying to do the following: I have a function $$\textrm{hann}[t,t_g,n_m]=\sum\limits_{n=1}^{n_m}a_n\left[1-\cos\left(\frac{2\pi ...
0
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0answers
82 views

Minimization of a non-linear objective function subject to linear constraints

I have solved a linear program in Mathematica using the LinearProgramming function with arguments of the form LinearProgramming[c,m,{{b1,s1},{b2,s2},...}] i.e. ...
2
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1answer
56 views

Working precision and pure functions in FindMinimum

I have this function: fun = (# - 5.0)^2.0 & Then, I want to find the minimum: ...
34
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3answers
2k views

Identifying critical points/lines of 2/3D image/cubes

Upshot I am interested in identifying critical points of a 3D field/cubes (maxima, minima, tube-like and wall-like saddle points) and 2D field/image (maxima, minima, saddle points). I.e. the ...
6
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3answers
211 views

How to use a compiled function in numerical optimization

I'm trying to wrap my head around function Compile. So, this is a spin-off question from: a previous question on using compile[] correctly. I have a function that ...
20
votes
4answers
4k 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 ...
5
votes
1answer
113 views

Optimizing code containing an infinite sum

I have the following expression. It's based on the negative-log-likelihood of a Poisson-Gaussian noise model, i.e. a convolution of a Poisson & Normal distribution. The value $x_{i}$ is the ...
1
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0answers
56 views

Optimizing evaluation of expressions dependent on four variables and containing double summation

I would like to optimize my code which I use to evaluate expressions containing double summation. These expressions are dependent on 3 space variables ($r$, $\theta$, $\phi$) and time $t$ and consist ...
4
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1answer
83 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 ...