Community Profile

# Alan Weiss

### MathWorks

1,799 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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How can i find the optimal parameters that minimize SSE?
I think that you did not understand the comment about not loading the data within your objective function. You should load it on...

23 days ago | 0

How can i find the optimal parameters that minimize SSE?
To solve an optimization problem you have to force your problem into the form required by optimization solvers. Sorry, that's ju...

23 days ago | 1

is it possible to determine the values ​​of the input parameters ca, cb, cc and cd for which the cc value at the output would be maximal?
Yes, take a look at this example, which has a much more complicated objective function. If your objective function is only the v...

24 days ago | 0

Travelling salesman problem - Detecting subtour
If you have an Optimization Toolbox™ license, take a look at this example, which has code that does what you ask. Access the cod...

24 days ago | 0

Optimization with very flat objective function
You can try scaling the function by multiplying it by a large value. You can also set some different options, such as TolFun. An...

26 days ago | 0

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Resolution of optimization variable in nonlinear optimization problem like simulannealbnd patternsearch
For patternsearch you can set the MeshTolerance option to 1/2 or something like that.If your objective function is very expensiv...

26 days ago | 0

SVM train and Classification Errors
Try removing the line species = ClassificationSVM(svmStruct,feat,'showplot',true); To learn how to use the resulting SVM, see...

1 month ago | 0

Question regarding passing input arguments in fmincon
I am not sure that I understand what you mean by "I want to pass ODEs as a constraint to fmincon." What about the ODE solution i...

1 month ago | 0

Why are fitcsvm Hyperparameters trained on the whole dataset and used for crossvalidation?
Perhaps I didn't explain well what the example is supposed to be showing. The second "fitting" step that you object to is not fi...

1 month ago | 1

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How to solve 4 equations with 4 unknowns with bounds?
You set options for fsolve, but then call lsqnonlin. This is a mistake. You do not pass options to the solver. This might be a ...

1 month ago | 1

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How do I put a series of sum into a function?
I did not try to run your code, but I have several comments. Use the appropriate solver for your objective. For a quadratic obj...

1 month ago | 0

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fmincon performance varies when reformulating interval constraint
fmincon is a gradient-based solver, and as such does not work well with discontinuous functions. Locally, it attempts to minimiz...

1 month ago | 1

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Incorrect solution for symmetric problems in fmincon
fmincon is a gradient-based algorithm. When your initial point is [0.5,0.5], the gradient is zero, and fmincon stops, since it i...

1 month ago | 1

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How fmincon shifts x0 when it does not strictly satisfy the upper and lower bounds?
I believe that if you get this message, then you have made an error. You gave a start point that is infeasible with respect to t...

1 month ago | 1

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How to optimize parameters in ODE
Well, depending on what it means to optimize, I suspect that you can. I mean, are you trying to maximize a final value of one of...

1 month ago | 0

How to code a multi-objective mixed integer linear (MILP) programming problem in MATLAB?
You might find this example to be relevant. Instead of using fgoalattain, you can use intlinprog on an objective function that i...

1 month ago | 1

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Simulate welded beam design optimization problem using Matlab or Simulink
If you can create the geometry somehow, then I believe that the structural mechanics part of Partial Differential Equation Toolb...

1 month ago | 0

fminunc stopped because it cannot decrease the objective function along the current search direction.
Without running your example, I wonder if you could make two little changes to see if things are OK: Change the initial point t...

1 month ago | 0

Put weight sum in Genetic algorithm
You seem to be mixing up solving a multiobjective problem by using gamultiobj once and solving it by using fmincon repeatedly. ...

1 month ago | 0

Is it posible to optimize kinetic parameter in following ordinary differential equation?
I think that you would do better to use ode45 to solve your ODE, and use lsqcurvefit to optimize your parameters, as in this exa...

1 month ago | 0

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How to enter a matrix of variables within the linear equality function in genetic algorithm ?
You should not use a genetic algorithm to solve this equation. Instead, use lsqnonlin, which accepts bound constraints. Alan We...

1 month ago | 0

Invalid value for OPTIONS parameter PopInitRange: must be an array of finite doubles with two rows.
Are you performing a multiobjective optimization? If not, then your fitness function should return a scalar, not two outputs. If...

1 month ago | 0

How to give constraint of an interger to 'gamultiobj'?
Sorry, gamultiobj does not accept integer constraints. Alan Weiss MATLAB mathematical toolbox documentation

1 month ago | 0

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How is "feasibility" defined in fmincon?
Or see the documentation of iterative display for fmincon. Alan Weiss MATLAB mathematical toolbox documentation

1 month ago | 0

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Different optimization methods not working when I change derivative discretization.
I do not understand why you are creating approximate derivatives yourself. fmincon and the other optimization functions perform ...

1 month ago | 0

Optimize function with Bayesian Optimization
As clearly stated in the documentation for bayesopt, the function passes a TABLE of values. However, rastriginsfcn expects a 2-D...

1 month ago | 0

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use of fminunc with more than one variables
Please see the documentation on writing scalar objective functions. If you have Release 2019a, you can also use the problem-bas...

2 months ago | 0

GA violates the linear inequality constraints
You have expressed your constraints as nonlinear inequality constraints, not as linear inequality constraints. If the constraint...

2 months ago | 0

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How to set up user-supplied Hessian in fmincon for a minimization problem with nonlinear objective and nonlinear constraint?
For general advice related to this sort of problem, see Converged to an Infeasible Point. Alan Weiss MATLAB mathematical toolb...

2 months ago | 0