rcorless

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4 years, 178 days

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Editor-in-Chief of Maple Transactions (www.mapletransactions.org), longtime Maple user (1st use 1981, before Maple was even released). Most obscure piece of the library that I wrote? Probably `convert/MatrixPolynomialObject` which is called by LinearAlgebra[CompanionMatrix] to compute linearizations of matrix polynomials in several different bases. Do not look at the code. Seriously. Do not look. You have been warned.

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These are Posts that have been published by rcorless

I'm happy to announce the publication of Volume 5, Issue #1 of Maple Transactions.  You can find it at

mapletransactions.org
 

We have a survey paper by Veselin Jungic and Naomi Borwein on teaching Experimental Mathematics courses as our Featured Contribution.  Many of you will find it interesting and useful.

In the refereed paper section we have a paper on Metaprogramming with Maple and C by Ilias Kotsireas; a paper on fast transposed Vandermonde solving by Hyukho Kwon & Michael Monagan; a paper by David Ulgenes (an honours student in Oslo) on Gamma, Pseudogamma, and Inverse Gamma functions; and a paper by John Campbell on applications of Gosper's nonlocal derangement identity (which, if you don't know that the word "derangement" has a technical mathematical meaning, may give you the wrong impression!).

As usual I've also written something, and I hope you like it: it's about Chladni figures and standing modes in an elliptical drum, and visualizing such in Maple.  It uses Mathieu functions in Maple and noodles a bit about zerofinding (but winds up using fsolve because that's so convenient).
 

Keep the papers coming.  This is the 12th issue of Maple Transactions, and I remind you that it has a "Diamond Class" designation, which means there are no page charges to authors, and the articles are free to read for everyone.  This means that there's some volunteer labour needed, of course: you have to write the articles, and what we want is that you write articles that people in the Maple community actually want to read.

I'd also like to thank the copyeditor, Michelle Hatzel, for her very hard work on this issue.  She's really made a difference, and I think you will be able to see it.   

 

Maple Transactions Volume 4 Issue 4 has now been published.

 

This issue has two Featured Contributions by people who have been plenary speakers at Maple Conferences in the past, namely Veselin Jungić and Juana Sendra. We hope you enjoy both articles.  There is an accompanying video by Professor Sendra, which we will add a link to when it becomes ready.

As usual, there is an article in the Editor's Corner, but this one is a bit different.  In this one, Michelle Hatzell (the new copyeditor for Maple Transactions, who is also a Masters' student working with me at Western) and I have written about a fun use of Maple's colour contour plots to make an image that might be used as the cover of an upcoming book, namely Perturbation Methods using backward error, which I'm just finishing now with Nic Fillion and which SIAM will publish next year.  So, while there's some math in that paper, it's more about Maple's utilities for colour plotting; so you might find it useful.  We also hope you like at least some of the images.  Some are more attractive than others!

We have several Refereed Contributions, not all of which are ready at this time of publication but which will be added as they are revised and sent in.  We have a nice paper on using continued fractions in a high school context, another on code generation, and another on using Digital Signal Processing in Engineering courses.

Finally we have a first publication in French, by Jalale Soussi.  Actually we have the paper also in English: we chose to publish both, in our Communications section, each with links to the other.  It is possible to publish in Maple Transactions solely in French, of course, but the author provided both, so why not?

Happy reading, and best wishes for 2025. 

I was working in my living room.  My computer was upstairs, but I had my phone and tablet.  I'm working on The Book ("Perturbation methods using backward error", with Nic Fillion, which will be published by SIAM next year some time).

I've discovered something quite cool, historically, about the WKB method and George Green's original invention of the idea (that bears other people's names, or, well, initials, anyway).  (As usual.)  Green had written down a PDE modelling waves in a long narrow canal of slowly varying breadth 2*beta(x) and slowly varying depth 2*gamma(x).  Turns out his "approximate" solution is actually an exact solution to an equation of a very similar kind, with an extra term E(x)*phi(x,t).  The extra term depends in a funny way on beta(x) and gamma(x), and only on those.  So a natural kind of question is, "is there a canal shape for which Green's solution is the exact solution with E(x)==0?"  Can we find beta(x) and gamma(x) for which this works?

Yes.  Lots of cases.  In particular, if the breadth beta(x) is constant, you can write down a differential equation for gamma(x).  I wrote it in my notebook using y and not gamma.  I wrote it pretty neatly.  Then I fired up the Maple Calculator on my little tablet, opened the camera, and pow!  Solved.

I wrote the solution down underneath the equation.  It checks out, too.  See the attached image.

Now, after the fact, I figured out how to solve it myself (using Ricatti's trick: put y' = v, then y'' = v*dv/dy, and the resulting first order equation is separable).  But that whole "take a picture of the equation and write down the solution" thing is pretty impressive.

 

So: kudos to the designers and implementers of the Maple Calculator.  Three cheers!

 

Maple Transactions has just published the Autumn 2024 issue at mapletransactions.org

From the header:

This Autumn Issue contains a "Puzzles" section, with some recherché questions, which we hope you will find to be fun to think about.  The Borwein integral (not the Borwein integral of XKCD fame, another one) set out in that section is, so far as we know, open: we "know" the value of the integral because how could the identity be true for thousands of digits but yet not be really true? Even if there is no proof.  But, Jon and Peter Borwein had this wonderful paper on Strange Series and High Precision Fraud showing examples of just that kind of trickery.  So, we don't know.  Maybe you will be the one to prove it! (Or prove it false.)

We also have some historical papers (one by a student, discussing the work of his great grandfather), and another paper describing what I think is a fun use of Maple not only to compute integrals (and to compute them very rapidly) but which actually required us to make an improvement to a well-known tool in asymptotic evaluation of integrals, namely Watson's Lemma, just to explain why Maple is so successful here.

Finally, we have an important paper on rational interpolation, which tells you how to deal well with interpolation points that are not so well distributed.

Enjoy the issue, and keep your contributions coming.

 

The Proceedings of the Maple Conference 2023 is now out, at

mapletransactions.org

The presentations these are based on (and more) can be found at https://www.maplesoft.com/mapleconference/2023/full-program.aspx#schedule .

There are several math research papers using Maple, an application paper by an undergraduate student, an engineering application paper, and an interesting geometry teaching paper.

Please have a look, and don't forget to register for the Maple Conference 2024.

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