Questions tagged [mathematical-optimization]
Questions on the optimization functions of Mathematica such as FindMinimum/FindMaximum, Minimize/Maximize, NMinimize/NMaximize, etc.
1,360
questions
0
votes
1answer
41 views
Plotting NMinimize function
I want to plot the following NMinimize function:
I used
GGPlot = Plot[GG[DM], {DM, 0.02, 10}, PlotRange -> All]
But I get nothing!
My code is
...
0
votes
1answer
53 views
Issue with NMaxValue Constrained to an ImplicitRegion
I am trying to find the maximum (and minimum) value of an interpolated function constrained to an ImplictRegion with a (partly) curved boundary. I have followed the documentation carefully and tried ...
0
votes
0answers
28 views
How to compute Max function of the following form:
I knew that in Mathematica, the "Max" function yields the largest element of any of the lists, for example, Max[x,y,z,....].
How do I implement this function with Mathematica? and what does this ...
1
vote
0answers
38 views
Minimize with constraints on parameters does not stop running [closed]
I have the following simple optimization problem, but when I tried to put the values into Mathmatica, it does not stop running for hours.
Actual problem is:
$\qquad min_{x1, x2, x3} : a1\,x1 + a2\,...
0
votes
0answers
38 views
Optimizing a nested function in mathematica getting stuck at local maximum and giving wrong answer
I am trying to maximize this function over the value "p":
...
2
votes
1answer
35 views
Nested maximum function not working
I am trying to maximize a function which is itself a maximized function. For example, see the below.
Can someone explain this error:
...
2
votes
0answers
38 views
ArgMax problem with Piecewise function
I'm having an issue with finding the maximizer of a very simple piecewise function.
...
1
vote
1answer
41 views
How to solve an optimization problem with multiple constraints? [closed]
I would like to minimize a function in four variables with respect to multiple constraints. $a+b+c+d\leq 1$ and $a, b, c, d \geq 0$, i.e. minimizing on the unit simplex in 4D. How do I incorporate ...
2
votes
1answer
54 views
Maximizing Output from ParametricNDSolve [closed]
Given a system of differential equations that are dependent on two parameters, such as the system below (the equation below is not that important, I am interested in a general procedure given a ...
2
votes
0answers
55 views
Multiple agents routing optimisation problem
We are given an array of nodes of the form {{xcoordinate,ycoordinate}, weight, "name"}. This represents nodes on a 2D euclidean coordinate system. Further, we are given a number n which is the number ...
6
votes
3answers
460 views
How to make the computation of a minimum efficient?
I have a $80\times 80$ matrix $A$ and a vector $P$ and I want to compute efficiently the following minimum
$$
\min\{n\in \Bbb N :\|A^nP\|_\infty < 1\}
$$
Then I defined my matrix and vector in ...
0
votes
1answer
71 views
Find (numerically) point where derivative is infinite
I have a function that is shown in the image, below.
The point I am interested in extracting (numeric fine) is, in this case, 200. This appears to be the point at which one derivative is infinite.
It ...
8
votes
1answer
289 views
Maximizing over a 1D region
Why does the following not compute?
MaxValue[-y^2, y ∈ Interval[{-1, 1}]]
I expect it to compute the maximum value of the funtion over the interval from -1 to 1 ...
1
vote
1answer
41 views
NDSolve with Events that reevaluate with different Discrete Variables
I have the following problem:
I have a set of ODEs and some discrete variables which I can solve successfully. Now I want mathematica to check at every $0.1 \,t$ time step, wether it would increase ...
3
votes
2answers
196 views
4
votes
1answer
63 views
Using preconditioners efficiently
I am trying to numerically solve a linear system of equations of the form
A x = a
where A is really ill-conditioned and ...
6
votes
5answers
179 views
Maximizing efficiency of a power-tower (tetration) calculation
I'm working on a power tower $\displaystyle z^{z^{.^{.^{.}}}}$ and wish to maximize the efficiency of my algorithm to compute a cycle map. This is a color-coded diagram of the cycle period of each ...
0
votes
0answers
57 views
NDSolve with Functions Depending on time and time dependent Functions
EDIT:
following the advice of using Raw Input Form, the equations have the following form
...
4
votes
1answer
55 views
Calculating the volume of a paraboloidal region
I have an inequality that defines a paraboloid. I would like to calculate the volume of the intersection of this paraboloid and a cylinder of radius R.
...
0
votes
2answers
94 views
Is it possible to minimize this function in Mathematica/wolframAlpha?
I want to minimize this function $f(x, y)=\left(n_{1}\right)\left(1-x(1-x)^{k_{1}}(1-y)^{k_{2}}\right)^{T}+\left(n_{2}\right)\left(1-y(1-x)^{k_{1}}(1-y)^{k_{2}}\right)^{T}$
Though it is a function in ...
7
votes
6answers
402 views
Finding a center and radius that minimizes total distance
I have a list of $d$-dimensional data points $x_i$, and I want to find a $d$-ball which minimizes the sum of the squares of distances between the surface of the ball and the points. In other words, I’...
0
votes
3answers
101 views
Find the minimum of an expression with multiple constraints
I need help to find a value for "d" which the expr has the minimum value at that "d" value. Constraints are added to the code
...
0
votes
3answers
71 views
Finding the maxima of a function of two variables
I am trying to understand how Mathematica finds the local maxima of a function of two variables, but I am a bit lost here.
For example, consider:
...
1
vote
1answer
65 views
Minimization problem!
Im probably not seeing the obvious question but i want to minimize an expression like:
Func[A_,B_,θ_,θ1_]:= A Cos[θ-θ1] + B Sin[θ]^2
where i do to minimize in ...
2
votes
2answers
100 views
How can I find the coefficients which minimize my non elementary integral?
I have the integral
which I express in Mathematica code as:
Integrate[
(-((x^2 (c + x^2 (b + a x^2)))/(m + x^2 (v + d x^2))) + Abs[x])^2,
{x, -1, 1}]
I ...
0
votes
2answers
96 views
1
vote
1answer
52 views
How to interpolate a set of points with given local extrema?
I have a set of points on the 0xy plane: say
(-3,0), (-2,4), (-1,0), (1,2), (3,0), (5,1), (6,0), (8,-2), (10,0)
I would like to use software, like Mathematica, ...
2
votes
2answers
42 views
Maximise a function over real and complex parameters [closed]
I have the function
f[b_x_] := Exp[-I b] Sin[I x],
where $x$ is real and $b$ is complex. I want to maximise the function $f$ over $x$ and $b$, but it is ...
1
vote
2answers
62 views
Plotting only one piece of an implicit 3d surface (the one value of the order parameter wich minimizes some free energy function)
I would like to plot a graphic of spontaneous magnetization vs T vs h for a Curie Weiss Model. The equation for stationary ...
1
vote
1answer
54 views
Question for function FindMaximum
I need some advice on using the function FindMaximum as follows.
I find the function y(x) from a differential equation as below, and then for each c and each xMax I have different solutions y(x) and ...
0
votes
0answers
45 views
Prime Number Generator using Sieve of Eratosthenes
I was trying to apply the Sieve of Eratosthenes to find the prime numbers within the range of 100. I understand that Mathematica has a built in procedure to find prime numbers, but I was trying to ...
2
votes
0answers
26 views
NMinimize : Finding which method was used [duplicate]
Is it possible to find out which method Mathematica used when using the NMinimize method? Ie, either Nelder-Mead, differential evolution, etc...
Thanks.
1
vote
1answer
36 views
Problem when using NMinimize in a RecurrenceTable
I have a problem when I'm trying to use NMinimize in my RecurrenceTable, like in this example :
...
0
votes
1answer
42 views
Position of maximum element in list under optimisation
For a list of several functions:
functions = {a[x,y,z],b[x,y,z],c[x,y,z],d[x,y,z]};
I want to maximize the maximum value of a function of three variables. This ...
0
votes
0answers
21 views
NMaximize scrambles constraints
There have been lots of questions around regarding the issue that NMaximize/NMinimize may give results - or at least evaluate ...
2
votes
0answers
44 views
Simultaneous Peak and Background Fit
I'm not sure if this is the proper way to do this, but I have a question related to another open question of mine.
In this post, I'm looking at analyzing some quantum dot UV-Vis absorbance spectra (...
3
votes
1answer
72 views
Proving the positive semidefiniteness of a 6X6 symbolic matrix
Specifically, I want to check the positive semidefiniteness of the following 6X6 symbolic matrix
...
0
votes
1answer
98 views
Maximize this function
For the following matrix
$$M = \begin{pmatrix}
f1[x,y,z] & f2[x,y,z]\\
g1[x,y,z] & g2[x,y,z]\\
h1[x,y,z] & h2[x,y,z]
\end{pmatrix}
$$
with
...
0
votes
1answer
38 views
Maximise over functions in Mathematica
Define the functions $h$, $j$, and $k$ that are each functions of 3 variables:
h[x,y,z]
j[x,y,z]
k[x,y,z]
How can I find the max of these functions? I want the ...
25
votes
2answers
881 views
Possible bug in NMaximize function?
Bug introduced in 12.0
In 12.0.0 for Microsoft Windows (64-bit) (April 6, 2019) writing:
...
0
votes
0answers
54 views
How to find, for a temp. equation, Maxmum valus of position and time?
I have to find the position x and the time t for which the temperature is a maximum. I have a function ...
1
vote
1answer
46 views
ArgMin over intervals and discrete sets
I was playing with ArgMin but I'm not sure how to use it for constrained optimization.
For example,
ArgMin[x^2, x]
returns <...
11
votes
1answer
122 views
Minimizing expression over symmetric matrices
I'm trying to solve the following maximization problem over space of symmetric matrices A and positive definite H
$$R=\max_{A\in S(R^d)}\frac{\text{tr}(HA)^2+2\text{tr}(HAHA)}{\text{tr}(AHA)}$$
So ...
0
votes
1answer
55 views
FindMinimum diverges
I just enocountered following issue, FindMinimjum explicitly diverges — final result is WORSE than initial supplied conditions.
During evaluation of In[37]:= ...
0
votes
1answer
38 views
Plot global maximum point and differential equation
I have two questions:
(1) I found the global maximum point of the following function
...
0
votes
0answers
34 views
Arrow key problem with mathematica 12 and bash version 5
I want to know if anyone experiences the issue with mathematica-12 with bash-5?
I am using the command line interface of mathematica. Now when I do up arrow or down arrow to go to history, it does ...
0
votes
1answer
54 views
NMinimize cannot be used within RegionPlot
My version of Mathematica (11.1) apparently cannot do NMinimize within RegionPlot. It did work before (!) my last software update.
Here is an example from user GioMott having the same (unanswered) ...
1
vote
2answers
43 views
Find maximum of x given a bunch of constraints [closed]
Trying to find maximum of x given that '''0<=x<=3''' and some other stuff. This works fine:
Clear[x, y]
FindMaximum[{x, 0<=x<=3}, x]
But this does ...
2
votes
1answer
47 views
Function of Maximum and Minimum Functions of Two Functions
I try to answer this question The Maximum and Minimum Functions of Two Functions
I wrote the following code
...
0
votes
0answers
41 views
Numerical maximization
I am facing a numerical maximization problem with constraints.
Using Method -> {"RandomSearch", "SearchPoints" -> 3}, AccuracyGoal -> 2 often does not find ...
