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Alan Weiss

MathWorks

Last seen: 7 dagen ago |  Active since 2011

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I write documentation for MATLAB mathematical toolboxes, primarily optimization. I have also written documentation for PDE, statistics, symbolic math, and econometrics.

My pre-MathWorks job was with Bell Labs, primarily in mathematical models of data traffic, with a strong interest in parallel computation and in rare events (large deviations).

I do not provide private consulting. If you have a question, please ask on a public forum such as MATLAB Answers.

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Answered
How to add graphs to genetic algorithm
The gaplotbestf plot is in the third row, second column of the Screenshot 2024-03-04 144951.png file that you attached. This plo...

9 maanden ago | 1

| accepted

Answered
Optimization FlowShop Problem- Error Received
You don't pass numJobs into your calculateMaxTardinessWithSequence function: function maxTardiness = calculateMaxTardinessWithS...

9 maanden ago | 0

| accepted

Answered
Why are the return results of the fcn2optimexpr function different between MATLAB2019b and MATLAB2023b?
I think that you need to turn off static analysis: [f,exitflag] = fcn2optimexpr(@mubiaofunction,x,Analysis="off") Alan Weiss ...

9 maanden ago | 0

| accepted

Answered
Global Optimisation and nested function problem
The reason objective_function can see those parameters is because you passed them into the Fitautocorrvins function, and that is...

10 maanden ago | 1

| accepted

Answered
Solve using genetic algorithm
I really don't understand what you are trying to do. You seem to be mixing up symbolic and numeric variables. If you want to use...

10 maanden ago | 1

Answered
Giving target function outputs to optimization algorithm
While I haven't tried this before, it sounds to me as if you could change your objective function to use a data set of known poi...

10 maanden ago | 0

Answered
Number of plots by gaplotpareto
If I understand your question, you are asking either How does the solver choose the number of points to plot? Or How does the ...

12 maanden ago | 1

| accepted

Answered
Optimization problem gets stuck before going into solver
It is apparent that solve is taking too long to calculate constraint derivatives using reverse-mode autodifferentiation. This mi...

ongeveer een jaar ago | 0

Answered
Optimizing the GRU training process using Bayesian shows errors
The error is coming from your code. Apparently, some points visited (that have, for example, NumOfUnits = 30, InitialLearnRate =...

ongeveer een jaar ago | 0

| accepted

Answered
Gaussian process regression - how to fit a basis function but not other parameters
I might misunderstand what you are trying to do, but perhaps you could use the OptimizeHyperparameters name-value argument to fi...

ongeveer een jaar ago | 0

Answered
When I use fmincon, the optimised result does not satisfy my non liner constraints
You would do better to use the default 'interior-point' algorithm, which arrives at a feasible solution. fun = @(x)4*x(1)+x(2);...

ongeveer een jaar ago | 0

Answered
How to use both pswplotbestf and pswplotranges for particleswarm?
The issue is that the pswplotranges output function was written incorrectly, and does not take into account that other plots mig...

meer dan een jaar ago | 0

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Answered
Genetic Algorithm (ga) terminating after a few generations
Almost certainly this is because you use nonlinear constraints. When you use nonlinear constraints, there are very few major ite...

meer dan een jaar ago | 0

Answered
HELP 3 variable optimization use fmincon
The short answer is you put all your variables into one variable, and call a solver on the one variable objective function. For ...

meer dan een jaar ago | 0

Answered
How is genetic algorithm function's ga optimfunctions used? How do I use that? What is the difference between optimset and optimfunction? Why do I receive error in this code?
The correct function name is optimoptions: ga_opt = optimoptions('ga','Display', 'off', 'Generations', 25, 'PopulationSize',50,...

meer dan een jaar ago | 1

Answered
How to obtain the optimised decision variable in the lower-layer when using genetic algorithm for a two-layer optimisation problem?
You can write these to an array, if you like. Something like this: function [DV_Up_Opt,Obj_Up_Opt,lowhistory] = myfun() lowhis...

meer dan een jaar ago | 0

| accepted

Answered
fmincon non-linear optimisation: issues with sqp and interior-point
It sounds like you have done a good job in analyzing the solver behavior. There is one more thing that I have found that sometim...

meer dan een jaar ago | 0

Answered
Solve linear equation optimization
You might find the examples in the linprog documentation useful. Alan Weiss MATLAB mathematical toolbox documentation

meer dan een jaar ago | 0

Answered
pattern search does not perform function calculation between iterations.
I suggest that you turn on iterative display. I suspect that most of the values patternsearch samples evaluate to NaN or Inf or ...

meer dan een jaar ago | 0

Answered
I want to fit my ode model to experimental data and derive parameters using lsqcurevfit and fmincon
There are some examples in the documentation of fitting ODE parameters to data: Fit ODE Parameters Using Optimization Variables...

meer dan een jaar ago | 0

Answered
Can I adjust patternsearch meshsize using output function (during optimisation)?
Sorry to say, but a patternsearch output function does not allow you to change the mesh size. However, as I think you know, the ...

meer dan een jaar ago | 0

| accepted

Answered
how does check gradient compare supplied gradients with finite difference gradients?
The CheckGradients option causes solvers to compare a finite-difference gradient estimate to the supplied gradient value, and if...

meer dan een jaar ago | 0

Answered
Running genetic algorithm and Simulink in parallel
I am not at all sure that it is possible to run ga in parallel when the objective function is given by a Simulink model. For a ...

meer dan een jaar ago | 1

Answered
optimising hybrid energy design using genetic algorithm
For an error of that type I think that you should learn to use the debugger. See Debug MATLAB Code Files and Set Breakpoints. A...

meer dan een jaar ago | 0

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Answered
Fitness Scaling Options for Genetic Algorithm
The documentation says this: 'fitscalingrank' — The default fitness scaling function, 'fitscalingrank', scales the raw scores b...

meer dan een jaar ago | 0

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Answered
Problems with lsqnonlin - initial parameters not changing
We don't see your ObjFunE code, so cannot be sure of what is going on. It seems that you are solving an ODE to create some outpu...

meer dan een jaar ago | 0

Answered
Issue with large memory required for non-linear optimizer
You have 150^2 optimization variables. I do not see your parameterfun function, but if it is not a supported function for automa...

meer dan een jaar ago | 1

| accepted

Answered
How to create a Triple Objective Genetic Algorithm establish constraints and plot 3D
I am sorry to say that I think that you need more help than we can give on this forum. If you want to have a productive interact...

meer dan een jaar ago | 0

Answered
How to create a Triple Objective Genetic Algorithm establish constraints and plot 3D
OK, it seems that you have decided to use the solver-based approach, which is just fine. You set some nondefault options. I am ...

meer dan een jaar ago | 0

Answered
How to prevent ga-Solver from accepting the first best solution?
It is possible that you unknowingly set some constraints that keep the solution you want from being considered. It is very hard ...

meer dan een jaar ago | 0

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