Questions on the optimization functions of Mathematica such as FindMinimum/FindMaximum, Minimize/Maximize, NMinimize/NMaximize, etc.
2
votes
3answers
132 views
How can I name “a[[i]]” the parts of Table “a”? Or how to make Table “a” grow inside FindMinimum?
Let's say I want to minimize a function that uses a Table named a with the Conjugate Gradient Method of ...
5
votes
3answers
396 views
Travelling salesman with start and end points for 30 points
I am doing a route optimisation for delivery vehicles and failing dismally. Please see problem statement below. My current solution uses FindShortestTour, but this does not have defined start and end ...
1
vote
0answers
206 views
Methods for NonlinearModelFit
I am using NonlinearModelFit for a thesis project.
I get quite different results if I change the Method to LevenbergMarquardt or QuasiNewton or ConjugateGradient ...
0
votes
1answer
93 views
Alleviating a bottleneck involving a function call with symbolic derivatives
I have a bottleneck problem involving a function call with symbolic derivatives.
I don't have much experience with Mathematica (or any dynamic language) and I'm certain that the way I've set this up ...
0
votes
1answer
58 views
2
votes
1answer
154 views
Problem using the DifferentialEvolution method of NMinimize [closed]
I have a function of 20 parameters, which 3 of the parameters are my physical parameters, and the others are pull terms to fix the errors. The goal is finding the global minimum of this function, to ...
0
votes
0answers
168 views
NonlinearModelFit and NMinimize [closed]
I'm doing a non-linear fit on some data. The calculation residual is low, but I prefer to minimize another objective function such as:
...
2
votes
0answers
144 views
Minimization in mathematica [closed]
I have recently had a strange problem with NMinimize. I have a very huge function with respect to 20 parameters. When I ...
0
votes
0answers
53 views
Mathematica, nested optmization [duplicate]
I want to use the solution of Maximize, defined as a function, in another function. Here's an example:
...
5
votes
0answers
202 views
Mathematica vs Sigmaplot (Non LinearModelFit)
I asked a question in a previous post that was closed because "The title of the question is not correct and the issue here is too trivial to help anyone later".
NonLinearModelFit
It's possible ...
3
votes
2answers
92 views
Find condition under which variables fall away
I have a somewhat lengthy expression, looking like
expr = 1 + x + b + Pi + 2*a
Is there some way of generating a relationship between ...
6
votes
2answers
171 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 ...
1
vote
0answers
104 views
RandomSeed is not giving me different initial values [closed]
I'm running a NMaximize problem using NelderMead. For a reason I don't understand when I try to set different initial points using RandomSeed and I check this with the step monitor the initial vector ...
1
vote
0answers
103 views
How to express this output in the form $X=A.x$?
This problem arose in my stereo vision project.
I have two matrices:
$$
A = \left(
\begin{array}{ccc}
\text{x1}*\text{p131}-\text{p111} & \text{x1}*\text{p132}-\text{p112} & ...
0
votes
0answers
95 views
Edit mathematica API
What is the Document Viewer in mathematica purposes other then looking up apis?
For example why can I edit the mathematica documentation, but the content doesn't sucessfully save?
Subgoal: In the ...
0
votes
0answers
82 views
Function Nodal2`NodalNetwork is not evaluating [closed]
I am using a default package Nodal2.m for nodal analysis of a Voltage Controlled Current Source, but it's giving the same statement back in output instead of Y ...
1
vote
1answer
114 views
Seemingly simple optimization problem is slow
I'm trying to generate a demand curve numerically, given a utility function. The function for the demand is defined like so:
...
1
vote
1answer
151 views
How can I fit a matrix function with multiple variables to given eigenvalues?
I have a 5x5 matrix function H[kx]
...
1
vote
1answer
216 views
Optimizing the fitting of Ordinary Differential Equation(NDsolve) involving interpolation functions
I am a newbie to this forum. I am trying to use NDsolve to solve some ODEs involving the interpolation function. Then, I will compare the fitted curve and data to determine the ODE coefficients.
...
3
votes
0answers
194 views
What in practice is the difference between NMaximize[] and FindMaximum[]? [closed]
NMaximize[f,x] maximizes f numerically with respect to x.
...
1
vote
0answers
51 views
Using lists as optimization parameters [duplicate]
Possible Duplicate:
Minimizing a function of many coordinates
Suppose that the function $F[\vec{x}]$ computes a certain polynomial of the elements of the list $\vec{x}$. How can I use ...
5
votes
1answer
127 views
FindMaxValue specifics
I'm using FindMaxValue to study the distribution of maxima of Abs[RiemannSiegelZ[t]] between consecutive values of ...
0
votes
0answers
112 views
Optimization problem—constraints not valid? [closed]
I have a model optimization problem: maximize rent, ri, through signals, si and sj, given ...
1
vote
0answers
133 views
How to find the minimum of a function that is a sum of an analytical function and a series expansion?
I need to get a minimum of function F[ang] which is defined as a function of angle:
...
-3
votes
1answer
404 views
How can Mathematica solve this set of differential equations? [closed]
I'm trying to solve this set of non linear differential equations, but apparently it won't solve. I really tried all the tweaks I could think of. Still no progress... So now I turn to you, can you ...
2
votes
0answers
182 views
Numerically/Analytically Solving a System of Equations
I have $6$ functions $f_i(x,y,z)$, $(i = 1, \ldots, 6)$ in three variables $x,y,z$, and I would like to find a simultaneous instance of these variables, say $(x_0, y_0, z_0)$, such that $f_i(x_0, y_0, ...
0
votes
1answer
85 views
Problem combining 2 models [closed]
I'm trying to combine 2 independent linear optimization models while individually they are working combined they are not.
My guess on the mistake is that the last part where I solve for the variables ...
2
votes
1answer
184 views
Restrictions problem
I tried to program a simple linear optimization model and don't know where my mistake lies.
The function should be a sum over "t" and "z" from the product of two constants ("e" and "H") and the ...
1
vote
3answers
473 views
Determining the local extrema of discrete data [duplicate]
Possible Duplicate:
Local max/min of Mathematica data sets
If I have a continuous function f (for example ...
0
votes
0answers
237 views
dummy variable or binary variable [closed]
In my optimization model, one of the additional constrains implies that all the variables "X" depend on the indexes "a" and ...
4
votes
1answer
155 views
Maximizing functions with Which statements
I'd like to be able to find the maximum value that my Capex function (see below) generates. This is a fairly simple function so I could just add it up but I have more complex functions of a similar ...
1
vote
1answer
325 views
How to find local minima of a multivariate function with singularity?
I am working on a logistic regression problem which requires minimizing a cost function J[{theta0, theta1, theta2}, X, y] to find the optimal value for fitting ...
2
votes
1answer
168 views
About high dimensional integrals
I want to be able to do high dimensional integrals like,
(..naively I wrote it as this..)
...
0
votes
0answers
307 views
Reduce/NSolve cannot solve a constraint problem?
I am trying to solve the following problem:
Minimize Integral[ (y''[x]+10)^2,x]
Where y''[x]+a*y'[x]+y[x] = 0, and the initial conditions for the DE are
...
14
votes
2answers
386 views
How can I speed up the classic GA for graph coloring?
I'm trying to compute the chromatic number of this graph (which is 28):
g = Import@"http://www.info.univ-angers.fr/pub/porumbel/graphs/dsjc250.5.col";
My genetic ...
2
votes
1answer
428 views
FindMaxValue and FindMaximum - how to find GLOBAL maximum and not just LOCAL maximum
I will not be able to provide a simple minimum working example here as this seems to be very specific.
I have an interpolating function which I substituted into a PDE and then plot said PDE at a ...
7
votes
1answer
419 views
How to speed up Minimum Spanning Tree algorithm?
How to speed up MST algorithm? I work with graphs and I have adopted Prim's algorithm for my needs, from here.
The graphs which I use are very dense (number of vertexes: $V=500$ and every vertex is ...
4
votes
1answer
232 views
0
votes
2answers
351 views
3
votes
1answer
339 views
How to use mathematica to create school time-table?
I wonder if it is possible to use Mathematica for helping myself to create school timetable. I have a feeling that it requires quite simple optimization algorithm, but I have never been into ...
1
vote
2answers
132 views
Scalar product of two vectors have the least value
In geometry 3D, let $A(1,2,-3) $ and $B(-1,4,1)$ are two points. In the plane $(P):2x-3y+3z-17=0$, find a point $M$ such that the scalar product of two vectors $AM$ and $BM$ will have the least value. ...
5
votes
1answer
331 views
Multi-objective genetic algorithm in Mathematica?
Is there any implementation of a multi-objective genetic algorithm for Mathematica?
6
votes
2answers
577 views
Implementation of a new Game of Life Rule
I need to implement a new "game of life" in Mathematica: I have three states — black, red and white. Black means go forward, red go back and white take no action.
I would like to implement the ...
2
votes
1answer
181 views
FindMinimum, NMinimize, etc. with external process
I was hoping to be able to use MMA's minimization power to work with an external process. I want to minimize the function 'TryThisNumber[x_]' which sends the value of x to something external and gets ...
4
votes
1answer
171 views
Optimizing a rank 3 tensor
Assume we have the following elements
\begin{equation}
F_i{}^j \;and\; S_{ij}{}^k,
\end{equation}
which represent the components of tensorial objects of ranks 2 and 3 respectively, with Complex ...
1
vote
3answers
159 views
How to find maximum ConditionalExpression among all solutions
For example I want to find solution with maximum value among solutions (and possibly plot it):
...
3
votes
2answers
185 views
Find all points that have the same minimum? [duplicate]
Possible Duplicate:
How to find all the local minima/maxima in a range
Sin[x] have two points ($3\pi/2,7\pi/2$) where the same minimum ($-1$) is achieved ...
2
votes
1answer
275 views
Problems with FindMinimum for Constrained Optimization
I am trying to define a simple optimization problem, arising from the discretization of a simple Optimal Control problem.
The problem that results is essentially linear, with bilinearities only ...
3
votes
1answer
225 views
wrong use of _?NumberQ?
I am having trouble with a numerical exercise. Here's a simplified version of my problem.
I define two functions to find the solution to two constrained maximization problems:
...
2
votes
1answer
218 views
Handing a list of constraint expressions to a C++ function with MathLink
I need to solve an optimization problem, which is defined in a Mathematica notebook.
Using Mathematica's FindMinimum is not an option, because it is too slow. So, ...
