# Alan Weiss

### MathWorks

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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**Feeds**

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...

7 maanden ago | 1

| accepted

Optimization FlowShop Problem- Error Received

You don't pass numJobs into your calculateMaxTardinessWithSequence function: function maxTardiness = calculateMaxTardinessWithS...

8 maanden ago | 0

| accepted

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 ...

8 maanden ago | 0

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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...

8 maanden ago | 1

| accepted

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...

8 maanden ago | 1

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...

9 maanden ago | 0

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 ...

11 maanden ago | 1

| accepted

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...

11 maanden ago | 0

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 =...

11 maanden ago | 0

| accepted

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

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

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...

ongeveer een jaar ago | 0

| accepted

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...

ongeveer een jaar ago | 0

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 ...

ongeveer een jaar ago | 0

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,...

ongeveer een jaar ago | 1

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...

ongeveer een jaar ago | 0

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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

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

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

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

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

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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

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

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

| accepted

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

| accepted

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

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

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

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

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