Alan Weiss

Last seen: Today

MathWorks

1.962 total contributions since 2011

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 define sqrt in Optimization?
I'm not sure what you are talking about. If you are trying to extend the problem-based method, then the short answer is you are ...

18 dagen ago | 0

Answered
Restriction of upper and lower boundary values to single decimal place in GA.
You are free to use Mixed Integer ga Optimization and have your integer problem variables be ten times your real variables. Ala...

18 dagen ago | 1

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Answered
Is it possible before to run the optimization with GA or whatever meta-heuristic methods (algorihtm of optimization) you can choose or define the step or the increment of the bound of variables ?
You are free to use Mixed Integer ga Optimization and define your resulting variables as, for example, integer/100 or integer/20...

18 dagen ago | 1

Answered
Constrained Non linear least squares returns equation parameters much different from true set
I don't know exactly where your error is, but I reworked your code, and in my reworked version lsqnonlin returns the correct ans...

18 dagen ago | 0

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Answered
Using derivatives function, diff and GA toolbox
You don't show any code, so my answer might be irrelevant. Are you using diff as a symbolic derivative or as a standard MATLAB ...

18 dagen ago | 0

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Answered
Why isn't parallel computing taking place when using MADS search methods in patternsearch?
I think that you might have a slight misunderstanding of what some options mean, and also you need to set your options slightly ...

24 dagen ago | 0

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Answered
fminsearch options...supressing error messages
Are you passing the options to fminsearch? Please show your fminsearch call and options creation call. Alan Weiss MATLAB mathe...

25 dagen ago | 0

Answered
How to change the MaxSQPIter in the fmincon solver options?
If you look in the fmincon documentation of options you fiind that MaxSQPIter is a hidden option for the active-set algorithm. ...

25 dagen ago | 1

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Answered
Computational Efficiency for Decoupled Optimisation
Because the problems can be solved separately, then it will certainly save memory to solve them separately. Whether it saves tim...

25 dagen ago | 0

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Finding a single global solution
The answer is that you are using the wrong solver, and might have a wrong idea about what is possible. For almost all problems,...

26 dagen ago | 0

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Answered
Objective function for peak shaving and valley filling of wind turbine electrical load profile
Perhaps your objective should be a new variable m along with the constraint m >= f(i) % for all i where i is the time index an...

ongeveer een maand ago | 0

Answered
Energy storage optimisation problem - separate charge and discharge constraint
The error message is spot on: when you multiply variables, the problem becomes nonlinear. However, I am sure that you would rath...

ongeveer een maand ago | 0

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Answered
Look for Only Integer Values or Fixed Point Values in Paretosearch Algorithm
You could try setting the MeshTolerance option to a large value such as 1e-2 or even 1e-1. I'm not sure how it will affect the a...

ongeveer een maand ago | 0

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Answered
How to change patternsearch options for paretosearch algorithm?
Did you look in the documentation of options for paretosearch? It states clearly that MeshExpansionFactor is for patternsearch o...

ongeveer een maand ago | 0

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Answered
How can one write a program to do this? (fminbnd)
You can get the value of out = z simply by asking for it: [xbest,out] = fminbnd(@(x) test(x),0,1) See the fminbnd reference pa...

ongeveer een maand ago | 0

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Answered
optimal allocation of two assets by minimizing shortfall probability using fmincon
The problem is the you have not defined your objective function as a separate file that the optimization calls. You need to writ...

ongeveer 2 maanden ago | 1

Answered
Optimization of Simulink parameters using Global Optimization toolbox
There are a few examples in the documentation using Optimization Toolbox™ with Simulink®: Signal Processing Using fgoalattain ...

ongeveer 2 maanden ago | 0

Answered
Objective and constraints having a common function - Problem based in Matlab 2016b
Perhaps what you are looking for is in Objective and Nonlinear Constraints in the Same Function. Alan Weiss MATLAB mathematica...

ongeveer 2 maanden ago | 0

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Answered
nonlinear integer(boolean) programming problem
Is the cost linear in the decision variables? If so, use intlinprog. I assume that you have other constraints that you did not l...

ongeveer 2 maanden ago | 0

Answered
fmincon output is converging to infeasible point
While I don't understand your listed code at all, perhaps you will be able to solve your problem using some ideas from the docum...

ongeveer 2 maanden ago | 0

Answered
Optimising using a combination of linear equality constraints and no constraints
I don't know whether your objective function is smooth or not. If it is smooth (differentiable), I would suggest that you use fm...

ongeveer 2 maanden ago | 0

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Answered
Bayesian Optimization ionosphere example
I think that you need to do some reading in Model Building and Assessment. Please read about how to specify variables and object...

ongeveer 2 maanden ago | 0

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Bayesian Optimization ionosphere example
The bayesopt solver passes a table of values to the objective function. The x.n argument takes the 'n' field of the table x, an...

ongeveer 2 maanden ago | 0

Answered
How to know the current input for fminsearch?
For optimizing a simulation or ODE, you may want to try patternsearch and surrogateopt. For surrogateopt you will need to bound ...

ongeveer 2 maanden ago | 0

Answered
"Conversion to optim.problemdef.OptimizationExpression from sym is not possible." I am getting this error and I am not able to understand how to resolve this error.
You are mixing several data types in your problem. You cannot use optimization variables, symbolic variables, and numeric variab...

ongeveer 2 maanden ago | 1

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Answered
How to see the current value of the variable in "fminsearch" optimization?
You can do this using an Output Function. That example shows how to return the history of points, which is I think what you want...

ongeveer 2 maanden ago | 2

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Answered
How to select the design variables on an optimization problem?
That is a reasonable approoach. In fact, some solvers check for "fixed" variables (those with equal upper and lower bounds) and ...

ongeveer 2 maanden ago | 0

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Answered
How to set a fixed step for lower and upper bounds (lb,ub) in particle swarm optimization?
I am not sure that I understand you. I think that you mean that you have discrete variables, you would like your solution to be ...

ongeveer 2 maanden ago | 0

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Answered
Trying to view/display an optimization problem(lmi)
I know nothing about EHCM toolbox. But it is apparent that the toolbox does not use the problem-based approach. The functions sh...

2 maanden ago | 0

Answered
2D 'Surface Plot' from 3D geometry
There are some examples in the documentation that might be related to what you want. Alan Weiss MATLAB mathematical toolbox do...

2 maanden ago | 0