Rank: 3026 based on 43 downloads (last 30 days) and 3 files submitted
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optimization, evolutionary algorithms, machine learning

 

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08 Feb 2010 Screenshot CounterInBase: Counting in arbitrary base Counter in arbitrary base with a convenient interface. The counter state can be saved to disc. Author: Petr Pošík counter, number conversion, number base, base conversion 13 0
03 Feb 2010 savehold: Run the 'hold on' command and save its state for possible restoration A small utility encapsulating the call to 'ishold', 'hold on' and a restortion of the hold state. Author: Petr Pošík graphics, plot, plotting, hold, hold on, hold off 14 1
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5.0 | 1 rating
28 Jan 2010 Screenshot space125: Almost equally spaced points in logarithmic space Generate points ..., 1, 2, 5, 10, 20, ... often useful for log-plots when integer values needed. Author: Petr Pošík semilogx, semilogy, loglog, logspace, integer, ploting 16 0
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17 Oct 2013 MATLAB xUnit Test Framework MATLAB xUnit is a unit test framework for MATLAB code. Author: Steve Eddins

Hi all.

I am sorry it took me so long to post here the promised link to the mocking framework created by Vladimir Peric, a student of mine.

You can download mmockito from GitHub:
https://github.com/vperic/mmockito

It is a lightweight package, that definitely cannot do all the mocking things out there, but for the basic usage it shall be quite handy.

It is created using the new MATLAB unit test framework and should be compliant with it. It should also work with Steve Edins' MATLAB xUnit Framework, although maybe with a bit limited capabilities.

Feel free to report any issues directly on the GitHub page.

We hope you will find it useful.

31 Jul 2013 nearestSPD Finding the nearest positive definite matrix Author: John D'Errico

Hi John. I miss in the description how the "nearness" of the 2 matrices, U and Uj, is measured. Could you comment on that? Thanks, Petr

15 Feb 2013 MATLAB xUnit Test Framework MATLAB xUnit is a unit test framework for MATLAB code. Author: Steve Eddins

@Michael: A student of mine works on a mocking framework for MATLAB right now. Give us a few weeks. We will definitely post an announcement here.

29 Jan 2009 Calculation of Pareto points Function is intended for detecting Pareto points. Author: Eduard Polityko

Hi, Eduard,

1] Regarding the "Pareto optimal" and "non-dominated" distinction... I think I understand you. But there are two situations that should be distinguished:

a] We have very large (possibly infinite) space of candidate solutions, X, and their fitness values, F. This set X cantains the set of Pareto-optimal solutions, X*, X* \in X, which may be finite, but very often is infinite. The set X* is Pareto-optimal and of course it is also a set of non-dominated solutions.

b] On the other hand, in multiobjective optimization, you usually do not get the (whole theorethically possible) Pareto-optimal solutions; what you get is a finite set Xnd of solutions which are not dominated by any of solutions you came across during the optimization. The solutions in Xs are only approximation of the whole set X* of Pareto-optimal solutions. Sets X* and Xnd might be (and often are) different and IMHO this distinction is important.

If you consider the matrix of scores that is given to your function as the whole universe of possible solution evaluations, then you are right - the Pareto-optimal and non-dominated solutions are the same.

It is also true, that for many practical applications this distinction is quite subtle and not very important. I prefer to call the output of your function the non-dominated set.

2] Regarding the fact if two solutions which have the same fitness value can be part of the non-dominated (Pareto-optimal) set: on the page you pointed to, there is the following definition:

"A point x* is said to be (glob ally) Pareto optimal or a (globally) efficient solution or a non-dominated or a non-inferior point for (MOP) if and only if there is no x such that fi(x)<=fi(x*) for all i, with at least one strict inequality."

This definition is correct, but your interpretation is wrong. You say "The definition of Pareto points demands at least one strict inequality". But I would rather say "The definition of Pareto points demands NONEXISTENCE of other points with at least one strict inequality." Example:

Let's have a set of 2 points x1 and x2, and both points have the same evaluation, i.e. fi(x1)=fi(x2). Then the points do not dominate each other, right? Since, all their fitness scores are equal, there is no score in which the inequality is strict, right?

Consider the question if x1 is Pareto-optimal: The definition says that x1 is Pareto-optimal if there is no other point that would dominate x1. SInce there is only one other point x2 and since x2 does not dominate x1, then x1 is non-dominated and Pareto-optimal.

The similar holds for x2. So that both points are Pareto-optimal.

I hope we now understand each other.

Cheers, Petr.

26 Jan 2009 Calculation of Pareto points Function is intended for detecting Pareto points. Author: Eduard Polityko

Eduard,

two comments:

1] Your function does not compute pareto optimal points, but non-dominated points. These two words IMHO are not synonyms. The distinction is small, but important. Pareto front is the set of "best" points which are theoretically possible. A non-dominated front is only an approximation of Pareto front, which hopefully gets closer and closer to the Pareto front.

2] You are not right if you say that "if P=R then they are not Pareto because there are no strict inequalities". If they are equal, then none of them is dominated by the other, so that both of them can be part of the non-dominated front. Of course, if one of them is in the nondominated front, then the other is as well and if one of them is NOT it the nondom. front, then the other isn't either.

Regards,

Petr

Comments and Ratings on Petr's Files
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03 Feb 2010 savehold: Run the 'hold on' command and save its state for possible restoration A small utility encapsulating the call to 'ishold', 'hold on' and a restortion of the hold state. Author: Petr Pošík D'Errico, John

I'll admit, this is a simple thing. Nothing dramatic here, with only a couple of lines of simple code. But it might make your own code just a wee bit simpler to write and to read later on. And simple, modular code is always good. If holds on plots are something you do often, then you may like this utility.

I like the help. An H1 line, etc. The 5 rating is a tip of my hat to the author.

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