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Alan Weiss

MathWorks

Last seen: Today Active 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
Supplied objective function must return a scalar value
You have a misconception about what linear constraints mean and what a scalar objective function is. Linear constraints do NOT t...

2 días ago | 0

Answered
How to limit optimization program to choose only natural integers numbers (not float) if my objective function is not linear?
If you have Global Optimization Toolbox you can use Mixed Integer ga Optimization. Alan Weiss MATLAB mathematical toolbox docu...

2 días ago | 0

Answered
Why does the fmincon optimization give a slightly different solution in MATLAB 2019B as compared to 2020B?
Many things change in each version. The usual issue is that the underlying math libraries can have slight differences. Optimizat...

2 días ago | 0

Answered
hi, i have a problem with ga function. the problem is: Caused by: Failure in initial user-supplied nonlinear constraint function evaluation.
I believe that the error is here: function [c, ceq] = nlc(x) for j=1:320 c(1) = -sum(x(1,:)) +(320/43.65); ...

2 días ago | 0

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Answered
optimization of matrices with random initialization
You would probably do well to use the Problem-Based Optimization Workflow. But you can just as easily change your current soluti...

2 días ago | 0

Answered
How can I implement an "if" in optimization problem?
Yoou might be able to find some techniques in the new documentation topic Integer and Logical Modeling. Alan Weiss MATLAB math...

2 días ago | 0

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Answered
Linear fitting with 2 variables
I think that the Problem-Based Optimization Workflow would help. Write your optimization variables a, b, and c as you have done,...

7 días ago | 1

Answered
replicating excel solver using optimization linprog
I think that you would probably have an easier time formulating your problem by using the Problem-Based Optimization Workflow. ...

8 días ago | 0

Answered
problem using GA to optimize an image processing index in MATLAB?
I suspect that the problem is your objective function takes too long, possibly it does not even finish. I assume that you have ...

8 días ago | 0

Answered
Trying to solve Bethe equations - system of non linear equations
You are the unfortunate victim of a naming discrepancy. The fsolve you linked is for Optimization Toolbox, not Symbolic Math sym...

9 días ago | 0

Answered
How to use ObjectiveCutOff and ObjectiveImprovementThreshold from optimoptions in solver-based optimization problems
I think that you have a mistaken view of what these options do. Consult the options to see what they really do. I don't think th...

9 días ago | 0

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Answered
Error using ofun Too many input arguments.
I cannot reproduce your issue. When I try the following, I do not get an error: x = randn(20,1); r = ofun(x) function f = o...

10 días ago | 0

Answered
How to fit a generate polynomial coefficients of with general requirements
I could be wrong, but it sounds to me as if the Problem-Based Optimization Workflow would work well for you. You do not have an ...

10 días ago | 0

Answered
How to fit a function to 2D array when some parts of the underlaying function are known?
Well, it depends what you mean by "Z is proportional to c/X and Z is proportional to c2 + c3Y + c4Y^2". You could mean that Z is...

13 días ago | 0

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Answered
Relation between population size and function count for genetic algorithm
The answer is that some population members are "elite," and they do not have to be evaluated again. See How the Genetic Algorith...

14 días ago | 0

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Answered
Working of PSO with hybrid function
It means the hybrid function runs after particleswarm stops. Ends. Is done. That's what terminates means. In fact, it is equival...

15 días ago | 1

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Answered
Minimization and Optimization. Minimize output by optimizing inputs
Sounds like you would be best served with the Problem-Based Optimization Workflow. Declare the variables that can change as opti...

15 días ago | 0

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Answered
Unable to perform assignment because the size of the left side is 1-by-14 and the size of the right side is 14-by-14.
The error statement is clear: your assignment (equality) statement has a 1-by-14 vector on the left and a 14-by-14 matrix on the...

15 días ago | 0

Answered
fmincon is returning some garbage values in the final output
When I run your script I get the same results as you, so thank you for including all the relevant information. Note that your c...

15 días ago | 0

Answered
(OPTIMIZATION) Initial point is a local minimum - PROBLEM!!
I suggest that you plot the square of the objective function over a reasonable range of the parameter and over a small range suc...

17 días ago | 0

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Answered
solve a set of two linear equations
I don't really understand what you are trying to do, but it sounds to me like your best bet is to use the Problem-Based Optimiza...

18 días ago | 0

Answered
Solve taking too long, how to optimize code?
Another point of view in case Matt's solution is not satisfactory: work completely in floating point computation rather than sym...

24 días ago | 0

Answered
Refreshment of the objective function with FMINCON
I think that you have a mistaken view of what fmincon does. All optimization solvers take a fixed objective function and iterate...

24 días ago | 1

Answered
Optimisation: minimise function while maximising a design variable
Perhaps you can change the optimization in a nearly unnoticeable way that would bias solutions to have large values of R, like t...

25 días ago | 2

Answered
Problem using fminbnd function
All optimization solvers require that the objective function return a scalar value. You need to write your objective function in...

27 días ago | 0

Answered
Augmented Lagrangian and Penalty Methods
Sounds like a homework problem. I suggest that you consult the documentation for passing extra parameters, such as Passing Extr...

27 días ago | 0

Answered
Find gradient numerically for the equation
There are tools on the File Exchange that can help you find numerical approximations to derivatives. For example, see Adaptive R...

alrededor de 1 mes ago | 0

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Answered
optimization problem - problem using det funciton
The main problem is that det is not a Supported Operations on Optimization Variables and Expressions. For example, x = optimvar...

alrededor de 1 mes ago | 1

| accepted

Answered
How to optimize nonlinear multiple input model with multiple constraints
I doubt that you want a symbolic solution. You probably want numbers. So I suggest that you use the Problem-Based Optimization W...

alrededor de 1 mes ago | 0

Answered
can i use different solvers for problem based optimisation in matlab
You CAN use different solvers. The question is, SHOULD you? In other questions you have shown that you are trying to solve an MI...

alrededor de 1 mes ago | 0

| accepted

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