Alan Weiss

MathWorks

Last seen: 15일 전 | 2011년부터 활동

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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What is the output when Particle Swarm Optimization exceeds MaxTime
I believe that the code returns the point giving the best (lowest) objective function value encountered. Alan Weiss MATLAB mat...

15일 전 | 0

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Genetic algorithm only works with integer constraints..
Yakov, your report indicates that the nonlinearly-constrained problem is being solved in the usual way: having very few iteratio...

약 2달 전 | 1

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why doesn't the gamultiobj function give me the output of the algorithm?
Your script worked for me. I attach the result. Using these commands, I also got a plot of the Pareto front. opts = optimoption...

3달 전 | 0

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GA - objective and constraints have to run the same expensive function
This is a difficult problem because of the way that ga calls functions, both fitness and nonlinear constraint. For most solvers,...

3달 전 | 0

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A problem in official website 'Least-Squares (Model Fitting) Algorithms'
Thank you for pointing out this long-standing error in the documentation. I will fix the error as soon as practicable. Alan Wei...

3달 전 | 0

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Why is fmincon not finding the right solution?
Your mistake is trying to use fmincon to solve a problem with integer constraints. fmincon does not apply to this type of proble...

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What does useParallel doesn't work with Automatic Differentiation means and how do I fix it?
This is not a problem, this is a notification from internal algorithms. You are using the problem-based approach with supported ...

3달 전 | 0

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Spacecraft trajectory optimization with GA in Matlab (on/off constant thrust)
You might be interested in this example: Discretized Optimal Trajectory, Problem-Based. The problem formulation is different tha...

3달 전 | 0

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I want to find 4 constant with used 1 eq
This is an underdetermined problem, meaning there are many different values of x1, x2, x3, and x4 that work. For example, choose...

3달 전 | 0

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Trouble with plotting iterations in patternsearch optimization
I think that what is going on is that you have nonlinear constraints in your problem. When there are nonlinear constraints, patt...

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Setting conditions for optimization variables
x = optimvar('x', 100, 'LowerBound', 0); ub = Inf(100,1); ub(1:10) = zeros(10,1); x.UpperBound = ub; showbounds(x) It would...

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Supplying gradient for the subset of parameters
The short answer is no: there is no provision to provide analytic gradients for a subset of the parameters. I cannot think of a ...

4달 전 | 0

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Is there a way to specify objective and constraint gradients when doing nonlinear optimization in the problem-based framework?
The problem-based approach calculates and uses gradients automatically for supported functions. However, to include gradients of...

4달 전 | 0

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surrogateopt: output function
Try this. lb = [-3 -3]; ub = -lb; opts = optimoptions('surrogateopt','OutputFcn',@listout); obj = @(x)100*(x(2) - x(1)^2)^2 ...

4달 전 | 1

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Passing values to PSO options
It works for me. Here is a little test script: fun = @(x)x(1)*exp(-norm(x)^2); lb = [-5,-5]; ub = -lb; opts = optimoptions('...

4달 전 | 1

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Do I need to normalize input parameters to Particle Swarm Optimization?
You don't usually need to scale your parameters, but many problems are solved more reliably if you do. See Center and Scale Your...

4달 전 | 0

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Possible bug with coneprog?
I think that you have identified a problem with the default options for trajectory problems: the optimality tolerance should be ...

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How can I save the output parameters for each step using lsqnonlin function?
Write an output function to save the values, either to a workspace variable or to a file. For syntax details, see Output Functio...

4달 전 | 0

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I'm trying to apply conditional constraints on two variable with bayesopt
I think that you set the wrong name-value argument for your constraint function. bayesopt thinks that you are using an XConstrai...

4달 전 | 0

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parameter optimization in function
Try putting the following code at the end of yours: [dfinal,resnorm] = fminbnd(@(damping)trytofit(damping,x0,Acc_clean),0.00002...

4달 전 | 0

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Conversion from symbolic to matlabFunction and writing the result to a file
Would it be possible to do the following: create a multiplier variable m in addition to the other variables? syms Dm0 Ds0 Ds1 d...

4달 전 | 0

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Using Multistart in an unconstrained optimization
This type of problem is well-known to be numerically touchy, and to have multiple local minima. You really should give bounds, t...

4달 전 | 0

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How does using same variables for both objective and constraints affect optimization results?
By changing the objective you also change the steps that fmincon takes to solve your problem. You should not be surprised that t...

5달 전 | 0

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Power balance in a microgrid
Usually the way to include this type of equality constraint is to use the approach shown in Integer and Logical Modeling. For an...

5달 전 | 0

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GA doesn't proceed to the next generation
Thank you for providing a complete problem, including all supportng function files. My main question is, why are you trying to ...

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consider Z = x*y, a highly nonlinear relationship in MILP
Usually, when you have a MILP then you don't have variables multiply each other unless one of the variables is binary. For this ...

5달 전 | 0

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minimize linear objective function with quadratic constraint
Again, I am not sure that I understand you correctly. I do not know what your optimization variables are, and while you say that...

5달 전 | 0

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coneprog: Infeasibilities are satisfied in last step from iterative display but exitflag is still -2 (NoFeasiblePointFound)
I think that you have a misunderstanding about what the iterative display shows. For example, consider the documentation example...

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Changing optimization technique for Gaussian process regression model
I answered a similar question recently: https://www.mathworks.com/matlabcentral/answers/1751170-svm-and-knn-hyperparameter Alan...

5달 전 | 0

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Not reproducibility in Random Forest with Hyperparameters
In creating your template for training, did you set the Reproducible name-value argument to true? Also, for your parallel option...

5달 전 | 1

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Alan Weiss

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