MaplePrimes Posts

MaplePrimes Posts are for sharing your experiences, techniques and opinions about Maple, MapleSim and related products, as well as general interests in math and computing.

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  • Let us consider 

    MmaTranslator:-FromMma(" Table[0,{n=10},{m=2}]");
    
    [seq([seq(0,i=1..(m := 2))],j=1..(n := 10))]
    

    The above result is syntactically incorrect in Maple language. The translation should be 

    Matrix(10,2)
    #or
    [seq([seq(0,i=1.. 2)],j=1..10)]

    up to the Mmma's result

    Table[0, {n = 10}, {m = 2}]
    
    {{0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0,0}, {0, 0}}

    Another bug is as follows.

    MmaTranslator:-FromMma("Sinc[x]");
    
    Sinc(x)

    whereas the expected result is piecewise(x=0,1,sin(x)/x) up to http://reference.wolfram.com/language/ref/Sinc.html

    In general, the MmaTranslator package is outdated. It often returns working Mma's commands as incorrect (Concrete examples are long and need a context. These may be exposed on demand.). The question arises about the quality of other Maple translations. 

    The command

    plots:-implicitplot(evalc(argument((1+x+I*y)/(1-x-I*y))) <= (1/4)*Pi, x = -5 .. 5, y = -5 .. 5, crossingrefine = 1, gridrefine = 2, rational = true, filled, signchange = true, resolution = 1000);
    

    produces an incorrect result

    in view of

    evalf(argument((1-4+4*I)/(1+4-4*I)));
                              2.889038378
    

    There is a workaround 

    plots:-inequal(evalc(argument((1+x+I*y)/(1-x-I*y))) <= (1/4)*Pi, x = -5 .. 5, y = -5 .. 5);

     

    The command 

    restart; st := time(): FunctionAdvisor(EllipticE); time()-st;

    produces the result on my comp in 805.484 s. Too much time.

    The command

    J := int(sin(x)/(x*(1-2*a*cos(x)+a^2)), x = 0 .. infinity)assuming a::real,a^2 <>0;

    outputs 

    (infinity*I)*signum(a^3*(Sum(a^_k1, _k1 = 0 .. infinity))-a^2*(Sum(a^_k1, _k1 = 0 .. infinity))-a*(Sum(a^(-_k1), _k1 = 0 .. infinity))+a^2+Sum(a^(-_k1), _k1 = 0 .. infinity)+a)

    which is wrong in view of 

    evalf(eval(J, a = 1/2));
                           Float(undefined) I

    The correct answer is Pi/(4*a)*(abs((1+a)/(1-a))-1) according to G&R 3.792.6. Numeric calculations confirm it.

    Both the commands 

    maximize(x*sin(t)+y*sin(2*t), t = 0 .. 2*Pi)assuming x>=0,y>=0;
    minimize(x*sin(t)+y*sin(2*t), t = 0 .. 2*Pi)assuming x>=0,y>=0;

    output 0. Simply no words.

    The following three commands 

    plots:-implicitplot(3*cos(x) = tan(y)^3, x = -Pi .. Pi, y = -(1/2)*Pi-1 .. (1/2)*Pi+1, thickness = 3, crossingrefine = 1, rational = true, signchange = true, resolution = 1000, gridrefine = 2);
    plots:-implicitplot(3*cos(x) = tan(y)^3, x = -Pi .. Pi, y = -(1/2)*Pi-1 .. (1/2)*Pi+1, thickness = 3, crossingrefine = 1, rational = true, signchange = false, resolution = 1000, gridrefine = 2);
    plots:-implicitplot(3*cos(x) = tan(y)^3, x = -Pi .. Pi, y = -(1/2)*Pi-1 .. (1/2)*Pi+1, thickness = 3, crossingrefine = 1, rational = true, resolution = 1000, gridrefine = 2);

    produce the same incorrect plot 

    It is clear the sraight lines given by y=Pi/2 and y=-Pi/2 are superfluous. It should be noticed that the Mmma's ContourPlot command without any options produces a correct plot.

    Up to http://www.maplesoft.com/support/help/Maple/view.aspx?path=solve&term=solve

    • 

    If the solve command does not find any solutions, then if the second argument is a name or set of names, then the empty sequence (NULL) is returned; if the second argument is a list, then the empty list is returned. This means that there are no solutions, or the solve command cannot find the solutions. In the second case, a warning is issued, and the global variable_SolutionsMayBeLost is set to true.

     Let us consider 

    solve({x > -Pi, (tan(x)-tan(x)^2)^2-cos(x+4*tan(x)) = -1, x < Pi}, [x]);
                                   []
    

    We see the command omits the solution x=0 without any warning. It should be noticed that Mathematica solves it, outputting

    {{x -> 0}, {x -> 0}}

    and the warning

    Solve::incs: Warning: Solve was unable to prove that the solution set found is complete.

    One may draw a conclusion on her/his own.

     

    From October 19-21, the third installment of the Maple T.A. and Möbius User Summit took place. Making the move back to Europe this year, the three-day conference was held at the beautiful Vienna University of Technology in the heart of Vienna, Austria. The scope of this year’s event expanded to include Maplesoft’s newest product, Möbius, an online courseware environment, which is designed to help academic institutions move their STEM courses online.

    This year’s Summit brought together participants from 20 countries, including Australia, the Czech Republic, Poland, China, Norway, India, Egypt, Japan, the Netherlands, and many others. Needless to say, there is great interest in learning more about how Maple T.A. and Möbius can play a role in shaping the educational landscape.

    Video recordings of each presentation will be made public soon, so keep an eye out for them!

    Conference attendees take in the sights on the veranda at TU Wien

    Getting Down to Business

    Presentations were divided into 5 overarching themes as they relate to Maple T.A. and Möbius: Shaping Curriculum; Content Creation; Experiences Using Möbius; Integrating with your Technology; and The Future of Online Education. Presentations were given by representatives from schools across Europe, including DTU (Denmark), TH Köln (Germany), Imperial College of London and University of Birmingham (UK), Vienna UT (Austria), KTH Royal Institute of Technology (Sweden), Université de Lausanne (Switzerland), and others.

    Many talks showcased the impressive versatility of Maple T.A. as a online assessment system, and Möbius to have practical applications in all STEM subjects, from Nuclear Engineering to Operations Management and many subjects in between.

    Perhaps the discussion that gave Maplesoft the most feedback was led by Steve Furino from the University of Waterloo, who divided attendees up into groups to formulate a wish list of what they’d like to see in a courseware authoring environment. The list had over 40 items.


    Linda Simonsen, Country Manager in the Nordic, records a group’s wish list

    Notable Quotables

    Many thought-provoking statements and questions were posed, but the following few stood out above the rest:

    • “Wouldn’t it be wonderful if you could take the best course from the best instructor anywhere in the world?”
    • “With Maple T.A., we can divert resources away from grading and over to tutoring.”
    • “Möbius rescued us!”

    Get the party started!

    While each day was full of invigorating conference discussions, evenings provided ample opportunity to ditch the suit jacket and tie, and enjoy the lively Austrian atmosphere. The first evening at the Zwölf Apostelkeller was the perfect venue to break the ice while satisfying those taste buds longing for some traditional Viennese cuisine. Once Schnitzel, Käsespätzle (a delicious German version of Mac and Cheese), Strudel, Kaiserschmarren (shredded pancake), and a glass or two of wine hit the table, people soon forgot about the pouring rain outside.

    The evening reception took place 3-4 levels under ground

    Michael Pisapia, VP of Europe, serves digestifs to guests

    It would have been hard to top the social in the Apostelkeller, but the next evening sure tried.

    Day 2 finished with an impressive formal dining experience at the historic Gerstner Beletage in the Palace Todesco, built in 1864 and situated directly across from the Vienna State Opera House. The 500-room palace was home to Eduard Freiherr von Todesco, a well-known Viennese banker.

    View from the palace of the Vienna State Opera House

    Jonny Zivku, Maple T.A. Product Manager, gives opening remarks at the Gerstner Beletage im Palais Todesco

    Jonathan Watkins from the University of Birmingham and Michael Pisapia - both dressed to impress

    The skies finally cleared enough to take some photos, but only after most people had gone home. Thankfully Aron Pasieka, Möbius Project Manager, was still around to get some great shots of the city. Enjoy!


    Before the skies cleared vs. after the skies cleared

    From beginning to end, the entire Summit was very well received by everyone who attended.

    We would be remiss if we did not thank our incredible hosts at the Vienna University of Technology. Stefanie Winkler, Professor Andreas Körner, and Professor Felix Breitenecker were beyond helpful in bringing many of the finer details together, as well as helping many people overcome the language barrier.

    We can’t wait to do it all again in London, England in 2017, and hope to see just as many new faces as familiar ones.

     

    Photo credits: A. Pasieka, A. French, H. Zunic, J. Cooper

     

    Update: The conference presentation recordings are now available here on our website.

    Just a simple graphical view of Maple releases over the years.

    with(plots):
    MapleVersions := [[1, 1982], [1.1, 1982.05], [2, 1982.33], [2.1, 1982.42], [2.15, 1982.58], [2.2, 1982.92], [3, 1983.17], [3.1, 1983.75], [3.2, 1984.25], [3.3, 1985.17], [4, 1986.25], [4.1, 1987.33], [4.2, 1987.92], [4.3, 1989.17], [5.1, 1990.58], [5.2, 1992.83], [5.3, 1994.17], [5.4, 1996], [5.5, 1997.83], [6, 1999.92], [7, 2001.5], [8, 2002.25], [9, 2003.42], [9.5, 2004.25], [10, 2005.33], [10.01, 2005.58], [10.02, 2005.83], [10.03, 2006.17], [10.04, 2006.42], [10.05, 2006.5], [10.06, 2006.75], [11, 2007.08], [11.01, 2007.5], [11.02, 2007.83], [12, 2008.33], [12.01, 2008.75], [12.02, 2008.92], [13, 2009.25], [13.01, 2009.5], [13.02, 2009.75], [14, 2010.25], [14.01, 2010.75], [15, 2011.25], [15.01, 2011.42], [16, 2012.17], [16.01, 2012.33], [17, 2013.17], [17.01, 2013.5], [18, 2014.17], [18.01, 2014.33], [18.015, 2014.5], [18.02, 2014.83], [19, 2015.17], [19.1, 2015.33], [20, 2016.17], [20.1, 2016.25], [20.15, 2016.30]]
    a:=map(ListTools:-Reverse,MapleVersions): #swap x-y axis
    plot(a, style = point, symbol = point)
    

    This MaplePrimes guest blog post is from Ian VanderBurgh, the Director of the Center for Education in Mathematics and Computing (CEMC) and a Lecturer in the Faculty of Mathematics at the University of Waterloo. He has been overseeing a project to develop online, interactive mathematics curriculum for high school students, and has been integral in the development of Möbius, Maplesoft's online courseware environment.

    Start with one part interest in online education, add one part increased functionality for developing online content, and mix with one part increased focus in the media and elsewhere on mathematics education.  What does this produce?  The perfect time to create high-quality online resources to support learning and teaching in mathematics.

    The Centre for Education in Mathematics and Computing (CEMC) at the University of Waterloo aims to increase interest, enjoyment, confidence, and ability in mathematics and computer science among learners and educators in Canada and internationally.  For more than fifty years, we have been working with teachers to support the important work that they do in the classroom.  When online courses rose to prominence several years ago, we felt that this gave us the perfect opportunity to create materials to better support the curriculum being taught across Canada and around the world.

    The content for what we now call “Phase One” was planned: Advanced Functions (Pre-Calculus) as well as Calculus & Vectors.  These materials would support the education of students in their final year of secondary school, and also provide materials to reinforce concepts for students in STEM programs at the post-secondary level.

    After deciding on the content, we needed a platform.  We knew that we needed one with exceptional mathematical capabilities.  Thus, we have been working hand-in-hand with Maplesoft ever since.

    With content and platform established, the style began to take shape.  It is based around what one of my colleagues calls “the five Es”: Exposition (onscreen text with synchronized audio), Experimentation (worksheets where users can manipulate mathematical objects), Evaluation (re-generating quiz questions), Exercises (with answers and solutions), and Enrichment (application and extension problems and solutions).  Have a look at the materials and watch a video about the courseware.  After less than two years of “public life”, Phase One has received more than 2 million page views and usage is accelerating.

    But why stop there?  Through the development of Phase One, all of the stakeholders realized that, while what we created was great, we needed better and more efficient development tools.  Thus, Möbius was born.  (In the meantime, the CEMC separately launched Phase Two of this ambitious initiative: resources in computer science to support the teaching and learning of programming concepts.)

    Now, using the full capabilities of Möbius, we are developing Phase Three, a parallel set of resources to Phase One that will support mathematics at the Grade 7/8 level.  Why Grade 7/8?  We believe that these are very important years in education, that it is vital to future success in STEM disciplines that students flourish in these years, and that we should do whatever we can to support this.

    What comes next?  Time will tell.  But, the CEMC will be there supporting mathematics and STEM education.  STEM disciplines will drive almost everything in the twenty-first century, and we have an obligation to do whatever we can to give young people every possible chance for success.

    As mentioned a few weeks back, we have been working on an update to MaplePrimes designed to dramatically curtail the amount of spam we have been receiving. I'm happy to say that we implemented these features earlier today, and in the hour or so since publication, they have already helped prevent multiple messages from being posted.

    Using content posted to MaplePrimes over the past few months as a baseline, this new feature is successfully able to detect 90% of spam, while maintaining a false positive (i.e., incorrectly identifying a legitimate question or post) rate of 1%.

    If a message is detected as spam, it is immediately quarantined and not publicly posted. Importantly, any user who posts a message seen as spam is immediately informed, and is provided with a simple mechanism to let us know so that their post can be reinstated (if it is in fact legimate.)

    We will be closely monitoring these services to ensure that they are working as intended. In the meantime, I am very hopeful that they help improve the experience for our members, and require much less effort from our dedicated group of spam fighters.

    Hi Mapleprimes,

    I have made this little procedure with Maple. 

    check_g_conjecture_10.pdf

    similar to this next one check_g_conjecture_10.mw

    This may be worth a look.

    Regards,

    Matthew

    P.S.   see  https://en.wikipedia.org/wiki/Goldbach%27s_conjecture

    In My Humble Opinion, Wikipedia is a good crowd sourced resource.

     

    The content in all comments posted on any Blog posts are missing.  What happened to them?

    Below I have pasted the recent post of a spammer who's title was http:// 

    First of all, I thought those spam filters had taken care of those. 
    Secondly why isn't there an http:// with a zero rating user poster filter on this forum yet?

     

     

    When I made the suggestions about new ways to delete spam, I specifically requested that there be no confirmation dialogs. I even emphasized it. But I see that there is such a dialog. Was the author of the spam asked to confirm whether they wanted to make the post? So you're saying that my time is worth less than the spammer's. Every time that I need to answer that dialog, it's an insult, a slap in the face direct from Maplesoft.

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