Maple users may notice unexpected results when calculating standard deviations with weights.

This is because the notion of weights used by Maple is not exactly the commonly used notion of repeated measurements.

Maple uses the NAG library from the Numerical Algorithms Group to compute the standard deviation in the presence of weights. The formula that is used is given in their documentation: https://www.nag.com/numeric/cl/nagdoc_cl25/pdf/g01/g01aac.pdf.

Download standard-deviation-weights-help-example.mw

A user wondered how to have Maple produce a desired form of a solution

Download question-better-spacing.mw

We suggested the closest they might be able to get is using simplify like so:

Download suggestion.mw

Our user wondered about using PolynomialIdeals:

1.  If we have n+1 polynomials,  f, g1,...,gn,  how to determine if  f  is in the ideal generated by  g1,...,gn?

2.  If so, how to write  f  as a polynomial combination of   g1,...,gn? 

We suggested that;

The nicest interface to answer the first question is given by the ?PolynomialIdeals,Operators page: you can write

with(PolynomialIdeals):
with(Operators):
J := <g1, g2, ..., gn>;
f in J; # true or false

To answer the second question, you need to use the lower level  package (which underlies the  package). This will also answer the first question for you. In particular the  command. You can write:

(Edit Feb 1, 2022 - use  instead of 

with(Groebner):
G := [g1, g2, ..., gn];
ord := tdeg(x,y,z); # replace x, y, z with the appropriate variables; you can also use other variable orders -- see ?Groebner,MonomialOrders

b := Basis(G, ord);
n := NormalForm(f, b, ord, 'Q');
# if n = 0 then f is in the ideal; Q is the list of coefficients:
f - add(Q[i] * b[i], i = 1 .. numelems(b)); # this will be equal to n.

I’m looking for users’ favourite tips and tricks in Maple Learn. Specifically, small pieces of advice that most people don’t know about, but that helped you create better Maple Learn documents. For instance,

• A favorite feature that you think is hard to discover;
• Common techniques you use when creating documents;
• Things about Maple Learn you wish you knew when you started.

These tricks could be for newbies or for experienced users.

To start off the discussion, let me share three of my own favorite tricks in Maple Learn.

1. Using Documents from the Document Gallery

Writing a Maple Learn document from scratch can seem overwhelming, especially for beginners. A much easier way to create documents is to start with a template from the Document Gallery.

There are hundreds of Maple Learn documents in the Document Gallery, available here. Instead of writing Maple Learn documents from scratch, I like to search the gallery for documents relating to my topic. I then select a document, and just modify it slightly to get what I want.

2. Toggling from Math Mode to Text Mode

If you want to write text in a group element, it’s best to toggle to text mode (otherwise Maple Learn will treat your text as math).

While this can be done using the toolbar, there is a nifty keyboard shortcut to toggle to text mode: place your cursor at the beginning of the group element, and press the space key.

3. Using Double Arrows in Plots to Show Distance

Here’s one for the advanced users. The Vector Command lets you draw arrows on a Maple Learn plot. Combine two such arrows of the same colour going in opposite directions, and you get a double arrow (see below), which I like to use to represent distances in my Maple Learn documents.

Indeed, here is an example document where I use double arrows to provide a visualization of the product rule in calculus (plot pictured below). Notice how the double arrows (created using the vector command) represent distances in the plot.

Comment your favourite tips and tricks down below!

A user would like to know if it is possible to specify a data set say, x:=[1,2,3,4,5,6] and then extract a random sample from that data set, i.e. xsample:=[3,2,4] for a bootstrapping-type calculation.

We suggested they use something like the following:

Download array-random-sample.mw

A user wonders if there is a straightforward way to show US states with names using the WorldMap Data Set in Maple

We suggest something like the attached: map-of-us-with-states.mw

Although not mentioned in the documentation, the flexible beam component of MapleSim allows for simulation of large deflections.  

We’ve been busy! We have just released the 2021.2 updates for Maple, Maple Flow, and MapleSim. Here’s a quick overview. These updates are freely available to all customers who have the 2021 version of these products.

Maple

The Maple update includes a variety of corrections and improvements to the math engine and interface. It is available through Tools>Check for Updates in Maple, and is also available from the Maple 2021 download page, where you can also find more details.

In particular, this update includes fixes to the bug in the combine command when working with double summations, and the problems when performing context menu operations on values with units while in Document mode, both of which were reported on MaplePrimes. As always, we appreciate the feedback!

Maple Flow

The Maple Flow 2021.2 update offers a richer range of formatting features for creating professional-looking engineering documents, which have been requested by customers. Highlights include sections, controlling the display of commands, annotating images, and disabling automatic evaluation while making a series of changes.  This update is available from the Maple Flow 2021.2 download page, which also contains more details.

MapleSim

Lots of good stuff here that makes it easier to build and analyze models, including productivity features that speed up the creation of models that use hydraulics, support for the latest CAD file formats in the MapleSim CAD toolbox, the ability to model drift conditions with the MapleSim Tire Library, tools for simulating 3-D winding effects with the MapleSim Ropes and Pulleys Library, and a new MapleSim Web Handling Library add-on (which, I am sad to say, has nothing to do with Spiderman). See What’s New in MapleSim for details, and the MapleSim 2021.2 download page for instruction on how to obtain your update.

One of the things I love most about my job is working and collaborating with math teachers across the globe. Every discussion leads to additional insights into the challenges facing teachers today, and new ideas on how to make Maple and Maple Learn better. And sometimes, I even learn some math I thought I already knew!

A few months ago, I introduced Maple Learn to a friend of mine who teaches high school math in Kingston, Ontario. I showed her how she could use Maple Learn to teach many concepts during our call, including Completing the Square. I walked her through Maple Learn’s free-form canvas and explained how her students could work through a problem line-by-line just as they would in their notebooks. I highlighted the live plot window and showed how her students could graphically verify that their solution was equivalent to the initial expression. And, I demonstrated the power of Maple Learn’s intelligent context panel and how her students could check their answers algebraically. I thought I had done a good job, until she said: “Karishma, that’s not how we teach Completing the Square anymore!”. Huh! I was floored. What I had shown was the way I had learned the concept so many years ago. I was surprised to learn that there was a new way.

My friend then introduced me to Algebra Tiles and how she used it to teach Completing the Square. Once we went through a few examples, I realized that I had never fully appreciated what I was doing when I completed the square. I had memorized a series of steps without really understanding what I was trying to do. The progression of our discussion naturally led to the inevitable question: “Karishma, does Maple Learn include Algebra tiles? Because that would be a game-changer for my students. Currently, we use physical tiles, but with remote learning, we need something digital.” At that time, my answer was ‘not yet’; however, with the introduction of image support last week, I’m happy to announce that Maple Learn can support algebra tiles and other interactive supports.

Here is the Maple Learn document I created on Completing the Square using Algebra Tiles.

Feel free to change the expressions listed in the document and share it with your students. To see algebra tiles in action inside Maple Learn, take a look at the short video that I created.  If you have any suggestions for improving this application, please feel free to let me know.

This is my second try---my previous post about the Maple Conference  https://www.maplesoft.com/mapleconference/2021/ seems to have vanished into thin electrons.

Anyway!  The conference opens tomorrow!  There are many really interesting prerecorded talks, three live plenaries, two excellent panels, and registration is free!  See the above link.

I look forward to "seeing" you tomorrow.

Rob Corless, co-Chair of the Program Committee

on behalf of the organizers

Dear all,

The November issue of Maple Transactions is now up (we will be adding a few more items to that issue over the course of the month).  See https://mapletransactions.org/index.php/maple/index for the articles.

More importantly, Maple Primes seems to have a great many interesting posts, some of which could well be worked up into a paper (or a video).  Maple Transactions accepts worksheets (documents, workbooks) for publication, as well, although we want a high standard of readability for that.  I invite you to contribute.

The next issue of Maple Transactions will be the Special Issue that is the Proceedings of the Maple Conference 2021 (see my previous post :)

-r

From a tweet by Tamás Görbe : plotting Chebyshev polynomials in polar coordinates leads to some interesting pictures.  Screenshot here, link to the worksheet (and some perhaps interesting puzzles) at the end.

ChebyshevRose.mw

Calling all fans of customizable documents! What am I saying, we’re all fans of customizable documents here. Well, we’re all in luck, then, because with our latest updates to Maple Learn you can tailor even more details of your documents to your exact specifications. Read on to see what’s new!

As we all know, graphs are not merely a method of communicating mathematical concepts, but are of course an art form that can be used to display both mathematical and aesthetic beauty. But sometimes, you may find a little something getting in the way of that beauty… those darn gridlines. Even the most elegant of graphs can be tarnished by this faint, criss-crossing lines. But have no fear! With our latest updates, you can fix this problem with the click of a button. Simply select “Plot Settings” from the graph controls to the right of the plot window, and set Axes to “None”. Finally, your graph is pristine. What’s more, that’s not the only new feature we’ve added to the Plot Settings menu. You can also set the axes to “Boxed”, allowing you to see the gridline labels no matter how from the origin you are on the graph. You can also manually set the boundaries of your axes! No more scrolling and zooming to get the perspective just right.

As if that wasn’t enough, we’ve also added another exciting feature that will help make your graphs look exactly as you want them. By clicking the small graph icon to the left of your expression, you can customize the colour of your plot! You can choose from a wide variety of pre-set colours, or you can use our colour selector to get the exact shade you want. Any custom colours will be temporarily added to the bottom of the colour palette, so you can be sure that your graphs are consistent. At last, you can rest assured that your Maple Learn graphs won’t clash with your outfit.

What’s more, if you’re a fan of graph customizability, then this is the set of updates for you. We’ve added two more features that will help make your graphs both pretty and easy to understand. Tired of trying to draw shapes, only to have each side be a different colour? Well, no more! We’ve adjusted the Segment command to accept as many coordinates as you’d like, allowing you to create polygons (or just funky zigzags) to your heart’s content! As well, we’ve introduced a new command: the Label command. Now you can add text right onto the plot window and label your graph as you see fit. Or maybe you could use the Maple Learn plot window to start drafting a best-selling novel. The possibilities are endless!

We also wanted to take a moment to highlight our Example Gallery. We’ve made some changes to make it easier to find the examples you’re looking for. And with over 400 documents and counting, we’re sure to have what you want! But, on the off-chance we don’t, let us know! We’d love to hear about what you’d like to see. And as always, that goes for both the Example Gallery and for any features you’d like in Maple Learn itself! We appreciate your feedback.

Dear all,

Reversion of series---computing a series for the functional inverse of a function---has been in Maple since forever, but many people are not aware of how easy it is.  Here's an example, where we are looking for "self-reverting" series---which I called "ambiverts".  Anyway have fun.

https://maple.cloud/app/5974582695821312/Series+Reversion%3A+Looking+for+ambiverts

PS There looks to be some "code rot" in the branch point series for Lambert W in Maple, which we encounter in that worksheet.  Or, I may simply have not coded it very well in the first place (yeah, that was mine, once upon a time).  Checking now.  But there is a workaround (albeit an ugly one) shown in that worksheet.

Dear all,

Recently we learned that the idea of "anti-secularity" in perturbation methods was known to Mathieu already by 1868, predating Lindstedt by several years.  The Maple worksheet linked below recapitulates Mathieu's computations:

https://github.com/rcorless/MathieuPerturbationMethod

Nic Fillion and I wrote a more general introduction to perturbation methods using Maple and you can find that paper at 

https://arxiv.org/abs/1609.01321

and the supporting Maple code in a workbook at 

https://github.com/rcorless/Perturbation-Methods-in-Maple

For instance, one of the problems solved is the lengthening pendulum and when we do so taking proper account of anti-secularity (we use renormalization for that one, I seem to remember) we get an error curve that is bounded over time.

Hope that some of you find this useful.