Questions tagged [mathematical-optimization]
Questions on the optimization functions of Mathematica such as FindMinimum/FindMaximum, Minimize/Maximize, NMinimize/NMaximize, etc.
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Monitoring PolynomialReduce/Alternatives for other CAS packages
I have a large generic polynomial That looks like
$N = \sum_{i_1,i_2\cdots}c_{i_1,i_2,i_3,\cdots} {x_{1}}^{i_1}{x_{2}}^{i_2}\cdots $
This could have anywhere between 3000-9000 terms with a maximum ...
1
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2answers
46 views
Numerical Minimization of Large Expression
I want to minimize a function which contains ArcTan functions. The function is also very complicated.
I have the following code.
...
2
votes
1answer
64 views
How to maximize just with respect two parameters out of four?
There are some posts explaining how do we maximize a function of two parameters with respect to one of those and how to plot the resulting function: Plot a function after taking the supremum with ...
11
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1answer
209 views
Minimizing with differential evolution
A differential evolution algorithm is given here. I would like to get this kind of animation. I thought I could use NMinimize, given
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2
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1answer
40 views
How to Provide an RNN various type of inputs?
I'm trying to build an RNN in Mathematica.
My window is only 2 but the variables are of different types:
...
1
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0answers
31 views
Export system of inequalities in MPS format
I am interested in the .MPS format, usually used in Linear Programming problems (see here).
When importing a file in the .MPS ...
1
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2answers
62 views
Trouble finding a maximum of a constrained multivariate function
I have a multivariate function that I seek to maximize (ideally symbolically):
The function has the form:
$\frac{(-j*a)}{8 (-(b/2) - j (c-d-e)) ((j*b*c)/2 - (j*b*d)/2 + c*d - d^2 + a^2/4))}$
(...
1
vote
1answer
80 views
Minimize is running forever
My object function is $\frac{4 d k (1 - 2 r) r + k^2(3 r-1)r + d^2 (1 + r (6 r-5))}{ 2 (1-r)^2 r} + q* \frac{d^2 (2 - 3 r) + 2 d k ( 2 r-1) + k^2 (1 -(3 - r) r)}{(1-r)^2}$.
And I'm trying to find ...
8
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0answers
91 views
StableMarriage vs. FindIndependendEdgeSet: How to use the procedure FindIndependendEdgeSet as a Gale-Shapley algorithm?
From Help, the procedure StableMarriage was an element of the Combinatorica, but it is available in the built-in ...
4
votes
2answers
82 views
FindMaximum ignores MaxIterations option
I'm trying to find a maximum of interpolated function inside a particular mesh cell. However, for some cells the process is very slow and it returns a warning:
FindMinimum::eit: The algorithm does ...
11
votes
3answers
396 views
Minimum energy path of a potential energy surface
I have calculated the energies of a molecule by varying two parameters (Data points are here data). I want to find the minimum energy path from the point (180.0, 179.99, 21.132) to (124.5, 124.49, 0) ...
0
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1answer
22 views
Error from NMaximize inside function that calculate fwhm
I tried to use the function that is given in 1 in order to get the FWHM of some expression I got from solving a system of linear equations.
This is the function for calculating FWHM:
...
1
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3answers
70 views
3D Plot the result of local Minimize with varying parameter values
I'm faced with the following minimization problem: Find $r\in[0,1]$ that minimizes $\frac{d^2+k^2 (1-2r)r}{2(1-r)r}$, which is bounded by 0 and 1. In addition, $k<d$ holds and each of $d$ and $k$ ...
1
vote
2answers
99 views
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1answer
42 views
parameter fitting for a trascendental equation model
I want to solve the following problem with Mathematica: I have a physical model relating the $y$ variable with the $x$ variable given by the next expression:
$$y=...
2
votes
3answers
136 views
Finding minimum from ListPlot
I have Table with 10000 elements in it and I plot a graphic using ListPlot.
I need find minimum in graph.
Here is a .txt file with data.
I tried to use
...
0
votes
0answers
41 views
Not getting a solution to my maximization problem
I want to solve the following problem:
For $0.5<q<1$, $q<r<1$, $0\leq n$, $0\leq n_1<=\lfloor{n/2}\rfloor$, and $n_1,n\in\mathbb{N}$
calculate $\arg max_{n_1} S(q,r,n,n_1) $ as a ...
0
votes
1answer
92 views
Animate particle's trajectory
Does anyone know how to animate the trajectory of a particle, but make sure before the particle reaching a certain spot, there's nothing. I mean I want to make an animation that look like https://en....
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1answer
70 views
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0answers
90 views
Help in minimizing a cumbersome function
I'm trying to minimize a function in order to find a slope critical heigth on a solope stability analisys. The functions taken from (Chen 1975) are the following:
I added all the equations to mma but ...
0
votes
1answer
40 views
Maximize function subject to condition [closed]
What commands should I use in Mathematica to obtain the maximum or minimum of a function subject to conditions?
For example, find the maximum of the following function?
$\qquad T=\sqrt[3]{2\,x+5} + \...
0
votes
1answer
51 views
Minimization of objective function 300000 xy [closed]
How could I minimize the following in Mathematic?
300000 xy
under the constraints
...
1
vote
3answers
107 views
How to find the maximum?
I have in mind $$\max\left( \sqrt{(x-1) (y-x)}+\sqrt{(1-x) (7-y)}+\sqrt{(y-7) (x-y)}\right)$$
for $x\geq -2\land x\leq 3\land y\geq 0\land y\leq 11 $, of course, taking into account real values of the ...
0
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1answer
39 views
NMinimize in NMinimize …why doesn't work?
I want to use NMinimize in NMinimize.
What I want to do is
1) Make and Input the candidate of numbers to func by 1 st NMinimize.
2) replace numbers with the candidate.
3) evaluate and seek the "t" ...
1
vote
0answers
54 views
Integer linear programming can't find global minimum
I was working with Project Euler Problem 418 using Mathematica and got in trouble.
I wrote a function to find the unique factorization triple which minimizes c / a for integer n.
...
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3answers
69 views
1
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1answer
44 views
How to take a point randomly from a region [duplicate]
I want to take some points randomly by the limits above, I had try to use FindInstance method but it always out (0,0)
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0
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0answers
48 views
Rearrange a symbolic function in order that the result contains a minimum number of SQRT() and CBRT() calculations
I use mathematica for analytically calculating a function, which solves two equations:
...
0
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2answers
48 views
NSolve does not return a value
I'm interested in obtaining the KKT multipliers in a constrained optimization problem. I've checked the NMaximize documentation, but I've been unable to find how to ...
0
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0answers
16 views
Nmaximize with array in ConvexhullArea
I want to find maximum of convexhull area for n points.
I try to give a small example (n=4) as follow
...
0
votes
1answer
40 views
How to extract the minimal value from NMinimize? [closed]
According to the manual, if I calculate
NMinimize[x^4 - 3 x^2 - x, x]
that returns {-3.51391, {x -> 1.30084}}, I can extract the minimal value -3.51391 using
<...
1
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1answer
46 views
1
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0answers
46 views
L1-norm optimization algorithm crashes kernel on large datasets
I have an A.X-B linear system which I have transformed into A.x-b to be solvable as a linear program using the code below:
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1
vote
2answers
81 views
The Levenberg-Marquardt method for nonlinear least squares curve-fitting
There is a function with unknown coefficient $a$, $b$, $c$
$$t(k)=\frac{1}{a b}(c-arcsinh(\sinh(c \cdot e^{a\cdot k\cdot 2\pi}))$$
I have a measurements $t_k$ from observed data.
$(t_1 =0.4,t_2 =...
1
vote
2answers
108 views
Is it possible to find a closed solution for this problem?
I need to find the global minimum of the following function:
...
0
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1answer
94 views
Minimizing a function problem
I'm solving an elastoplastic problem of the Ducker Prager model using the closest point projection method, which consists of minimizing a distance between a trial stress and the yield surface in the ...
1
vote
0answers
71 views
How to find which automatic method is used by FindMinimum?
This question has already been addressed here and here. The second link consists of an answer by halirutan, which clearly states which method is used in which situation. However, while trying to check ...
0
votes
1answer
63 views
Finding the minimum points of a discrete trigonometric equation
Basically I'm trying to solve the equation
$$A\Big(\sin(\theta_a-\theta_{a+1}) + \sin(\theta_a-\theta_{a-1})\Big) + B\Big(n_a^z \sin(\theta_a) - n_a^x \cos(\theta_a)\Big) = 0$$
subjected to the ...
4
votes
1answer
111 views
Speedup of DimensionReduce
I am interested in accelerating DimensionReduce using the "TSNE" method. I have a matrix with a size of 30000 * 10, and I want to reduce to 30000 * 8. But the calculation is very slow, any suggestions ...
1
vote
2answers
45 views
Define x as a multiple of a number as a constraint in the Maximize function
I am trying to optimize a linearly constrained Production Function. I have three inputs and want them all to be multiples of 150. I can make all the inputs to belong to the Integer Domain but is there ...
1
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0answers
43 views
Making a function $ f(n) $ tangential to another function $ g(n) $ by choosing appropriate constants
I have two functions $ f(n) = 1/(1+n) + b, (n \geq 0,b \geq 0) $ and $ g(n) = pn^2 + qn + r $. Assuming that I know the value of $ p, q $, and $ r $, I am trying to find a value for the constant $ b $ ...
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0answers
24 views
NMinimize calling an own defined function [duplicate]
I want to call an own defined function through NMinimize. For the sake of simplicity, let us define the problem as follow:
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0
votes
1answer
45 views
How to save the output data of second order differential equation in Mathematica?
I am beginner in Mathematica. I am trying to save the output data as a text file but I could not save !
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3
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0answers
49 views
Plotting gradient and newton directions for parametric system of nonlinear ODEs
I have a bucket (system) of chemical kinetics models, a nonlinear dynamical system given by:
where kf >= 0 and kr >= 0 are the parameters. The initial conditions are A(0) = B(0) = 1 and C(0) = 0. I'...
0
votes
1answer
246 views
Translating the Newton-Raphson method from Matlab to Mathematica
I am trying to optimize the variables of two (or three depending on how you think about it) matrices using the Newton-Raphson Method. I made the bottom code in Matlab. The code is pretty simple it ...
5
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2answers
256 views
0
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1answer
30 views
How can I specify the region for every variable simultaneously in NMinimize?
I want to use NMinimize to find the unknown unitary matrix that solves a (possibly nonlinear) matrix equation. For example, the one that transforms the Pauli matrix ...
2
votes
2answers
168 views
How to find second,third,etc maximum peak of list
I need to find all values of peaks.
I have Table with 10000 elements in it and I plot a graphic using ListPlot.
Then I tried to ...
2
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2answers
136 views
0
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0answers
73 views
