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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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  • In this paper we will demonstrate the importance of using simple to complex algorithms applied to complex systems in civil and mechanical engineering. In order to develop solutions that developers need to be involved in issues of advanced dynamic computer science. We show how is that with the Maple scientific program and through component-based algorithms can generate power then then be inserted into specific algorithms. Will form patterns with movements of rotation and revolution of their axes, in each case to model and analyze the curves thereof comprising. With these modelalos and curve analysis we can predict manufacturing costs, freight, inter alia estrcturas which they can be used with the correct use of Maplesoft.

     

    IX_Fast_2016.pdf

    Solid_Algorithms_applied_in_complex_3D_structures_for_Civil_Engineering_with_Maplesoft.mw

    (in spanish)

    Lenin Araujo Castillo

     

     

     

     

    The Joint Mathematics Meetings are taking place this week (January 6 – 9) in Seattle, Washington, U.S.A. This will be the 99th annual winter meeting of the Mathematical Association of America (MAA) and the 122nd annual meeting of the American Mathematical Society (AMS).

    Maplesoft will be exhibiting at booth #203 as well as in the networking area. Please stop by our booth or the networking area to chat with me and other members of the Maplesoft team, as well as to pick up some free Maplesoft swag or win some prizes.

    Given the size of the Joint Math Meetings, it can be challenging to pick which events to attend. Hopefully we can help by suggesting a few Maple-related talks and events:

    Maplesoft is hosting a catered reception and presentation ‘Challenges of Modern Education: Bringing Math Instruction Online’ on Thursday, January 7th at 18:00 in the Cedar Room at the Seattle Sheraton. You can find more details and registration information here: www.maplesoft.com/jmm

    Another not to miss Maple event is “30 Years of Digitizing Mathematical Knowledge with Maple”, presented by Edgardo Cheb-Terrab, on Thursday, January 7 at 10:00 in Room 603 of the Convention Center.


    Here’s a list of Maple-related events and talks:


    Exploration of Mathematics Teaching and Assessment through Maple-Software Projects of Art Diagram Design as Undergraduate Student Research Projects

    Wednesday, Jan 6, 10:20, Room 2B, Convention Center

    Lina Wu

     

    30 Years of Digitizing Mathematical Knowledge with Maple

    Thursday, Jan 7, 10:00, Room 603, Convention Center

    Edgardo Cheb-Terrab

     

    MAA Poster Session – Collaborative Research: Maplets for Calculus

    Thursday, Jan 7, 14:00, Hall 4F, 4th Floor, Convention Center

     

    Challenges of Modern Education: Bringing Math Instruction Online

    Thursday, Jan 7, 18:00, Cedar Room, 2nd Floor, Sheraton Center

     

    Using Maple to Promote Modelling in Differential Equations

    Friday, Jan 8, 10:40, Room 617, Convention Center

    Patrice G Tiffany; Rosemary C Farley

     

    If you are presenting at Joint Math and would like to advertise your Maple-related talk, please feel free to comment below, or send me a message with your event and I’ll add it to the list above.

     

    See you in Seattle!

    Daniel

    Maple Product Manager

    This post is my attempt to answer the question from here .  

    The procedure  ContoursWithLabels  has 2 required parameters: Expr  is an expression in  x  and  y  variables,  Range1  and  Range2  are ranges for  x  and  y . In this case, the output is the list of floats for the contours and 8 black contours (with labels) (the axis of coordinates as a box). 

    The optional parameters: Number is positive integer - the number of contours (by default Number=8),  S is a set of real numbers  C  for contours (for which Expr=C) (by default  S={}),  GraphicOptions  is a list of graphic options for plotting (by default  GraphicOptions=[color = black, axes = box]),  Coloring  is an equality  Coloring=list of color options for  plots[dencityplot]  command (by default Coloring=NULL). 

    The code of the procedure:

    restart;

    ContoursWithLabels := proc (Expr, Range1::(range(realcons)), Range2::(range(realcons)), Number::posint := 8, S::(set(realcons)) := {}, GraphicOptions::list := [color = black, axes = box], Coloring::`=` := NULL)

    local r1, r2, L, f, L1, h, S1, P, P1, r, M, C, T, p, p1, m, n, A, B, E;

    uses plots, plottools;

    f := unapply(Expr, x, y);

    if S = {} then r1 := rand(convert(Range1, float)); r2 := rand(convert(Range2, float));

    L := [seq([r1(), r2()], i = 1 .. 205)];

    L1 := convert(sort(select(a->type(a, realcons), [seq(f(op(t)), t = L)]), (a, b) ->is(abs(a) < abs(b))), set);

    h := (L1[-6]-L1[1])/Number;

    S1 := [seq(L1[1]+(1/2)*h+h*(n-1), n = 1 .. Number)] else

    S1 := convert(S, list)  fi;

    print(Contours = evalf[2](S1));

    r := k->rand(20 .. k-20); M := []; T := [];

    for C in S1 do

    P := implicitplot(Expr = C, x = Range1, y = Range2, op(GraphicOptions), gridrefine = 3);

    P1 := [getdata(P)];

    for p in P1 do

    p1 := convert(p[3], listlist); n := nops(p1);

    if n < 500 then m := `if`(40 < n, (r(n))(), round((1/2)*n)); M := `if`(40 < n, [op(M), p1[1 .. m-11], p1[m+11 .. n]], [op(M), p1]); T := [op(T), [op(p1[m]), evalf[2](C)]] else

    if 500 <= n then h := floor((1/2)*n); m := (r(h))(); M := [op(M), p1[1 .. m-11], p1[m+11 .. m+h-11], p1[m+h+11 .. n]]; T := [op(T), [op(p1[m]), evalf[2](C)], [op(p1[m+h]), evalf[2](C)]]

    fi; fi; od; od;

    A := plot(M, op(GraphicOptions));

    B := plots:-textplot(T);

    if Coloring = NULL then E := NULL else E := ([plots:-densityplot])(Expr, x = Range1, y = Range2, op(rhs(Coloring)))  fi;

    display(E, A, B);

    end proc:

     

    Examples of use:

    ContoursWithLabels(x^2+y^2, -3 .. 3, -3 .. 3);

                                 

     

     

    ContoursWithLabels(x^2-y^2, -5 .. 5, -5 .. 5, {-20, -15, -10, -5, 0, 5, 10, 15, 20}, [color = black, thickness = 2, axes = box], Coloring = [colorstyle = HUE, colorscheme = ["White", "Red"], style = surface]);

                               

     

     

    The next example, I took from here:

    ContoursWithLabels(sin(1.3*x)*cos(.9*y)+cos(.8*x)*sin(1.9*y)+cos(.2*x*y), -5 .. 0, 2 .. 5, {seq(-2 .. 2, 0.5)}, [color = black, axes = box], Coloring = [colorstyle = HUE, colorscheme = ["Cyan", "Red"], style = surface]);

                                     

     

    There are many more examples can be found in the attached file. 

    ContoursWithLabels1.mw

     

    Edit. The attached file has been corrected.


    The year 2015 has been one with interesting and relevant developments in the MathematicalFunctions  and FunctionAdvisor projects.

    • 

    Gaps were filled regarding mathematical formulas, with more identities for all of BesselI, BesselK, BesselY, ChebyshevT, ChebyshevU, Chi, Ci, FresnelC, FresnelS, GAMMA(z), HankelH1, HankelH2, InverseJacobiAM, the twelve InverseJacobiPQ for P, Q in [C,D,N,S], KelvinBei, KelvinBer, KelvinKei, KelvinKer, LerchPhi, arcsin, arcsinh, arctan, ln;

    • 

    Developments happened in the Mathematical function package, to both compute with symbolic sequences and symbolic nth order derivatives of algebraic expressions and functions;

    • 

    The input FunctionAdvisor(differentiate_rule, mathematical_function) now returns both the first derivative (old behavior) and the nth symbolic derivative (new behavior) of a mathematical function;

    • 

    A new topic, plot, used as FunctionAdvisor(plot, mathematical_function), now returns 2D and 3D plots for each mathematical function, following the NIST Digital Library of Mathematical Functions;

    • 

    The previously existing FunctionAdvisor(display, mathematical_function) got redesigned, so that it now displays more information about any mathematical function, and organized into a Section with subsections for each of the different topics, making it simpler to find the information one needs without getting distracted by a myriad of formulas that are not related to what one is looking for.

    More mathematics

     

    More mathematical knowledge is in place, more identities, differentiation rules of special functions with respect to their parameters, differentiation of functions whose arguments involve symbolic sequences with an indeterminate number of operands, and sum representations for special functions under different conditions on the functions' parameters.

    Examples

       

    More powerful symbolic differentiation (nth order derivative)

     

    Significative developments happened in the computation of the nth order derivative of mathematical functions and algebraic expressions involving them.

    Examples

       

    Mathematical handling of symbolic sequences

     

    Symbolic sequences enter various formulations in mathematics. Their computerized mathematical handling, however, was never implemented - only a representation for them existed in the Maple system. In connection with this, a new subpackage, Sequences , within the MathematicalFunctions package, has been developed.

    Examples

       

    Visualization of mathematical functions

     

    When working with mathematical functions, it is frequently desired to have a rapid glimpse of the shape of the function for some sampled values of their parameters. Following the NIST Digital Library of Mathematical Functions, a new option, plot, has now been implemented.

    Examples

       

    Section and subsections displaying properties of mathematical functions

     

    Until recently, the display of a whole set of mathematical information regarding a function was somehow cumbersome, appearing all together on the screen. That display was and is still available via entering, for instance for the sin function, FunctionAdvisor(sin) . That returns a table of information that can be used programmatically.

    With time however, the FunctionAdvisor evolved into a consultation tool, where a better organization of the information being displayed is required, making it simpler to find the information we need without being distracted by a screen full of complicated formulas.

    To address this requirement, the FunctionAdvisor now returns the information organized into a Section with subsections, built using the DocumentTools package. This enhances the presentation significantly.

    Examples

       

    These developments can be installed in Maple 2015 as usual, by downloading the updates (bundled with the Physics and Differential Equations updates) from the Maplesoft R&D webpage for Mathematical Functions and Differential Equations


    Download MathematicalFunctionsAndFunctionAdvisor.mw

    Edgardo S. Cheb-Terrab
    Physics, Differential Equations and Mathematical Functions, Maplesoft

    Just a simple little proc that grabs and displays some simple data for general stars (I've only listed a couple for starters).  It wasn't till later that I realized it's not an up to date database as it doesn't contain more recent interesting stars like Kepler 452.  One would have to go to the SIMBAD astronomical database for which I have not yet devoted any time for .. at least not yet. 

    StarData := proc (a::string) local b, c, d, e1, e2, e3; b := StringTools:-DeleteSpace(StringTools:-Substitute(a, " ", "+")); c := HTTP:-Get(cat("http://www.stellar-database.com/Scripts/search_star.exe?Name=", b)); d := convert(c[2], string); e1 := d[StringTools:-Search("<H1>", d)+4 .. StringTools:-Search("</H1>", d)-1]; e2 := d[StringTools:-Search("Right", d) .. StringTools:-Search("Standard error in distance", d)-8]; e3 := StringTools:-SubstituteAll(StringTools:-SubstituteAll(StringTools:-SubstituteAll(e2, "<BR>", ""), "<B>", ""), "</B>", ""); print(e1); print(e3) end proc:

    StarData("Sun")

    "Right Ascension and Declination: 0h0m0s, +0&deg;0'0" (epoch 2000.0)
Distance from Sol: 0 light-years (0 parsecs)
"

    (1)

    StarData("Wolf 1061")

    "Right Ascension and Declination: 16h30m18.097s, -12&deg;39'45.17" (epoch 2000.0)
Distance from Sol: 13.91 light-years (4.264 parsecs)
"

    (2)

    StarData("Alpha Centauri")

    "Right Ascension and Declination: 14h39m35.88s, -60&deg;50'7.4" (epoch 2000.0)
Distance from Sol: 4.395 light-years (1.347 parsecs)
"

    (3)

    StarData("Sirius")

    "Right Ascension and Declination: 6h45m8.871s, -16&deg;42'57.99" (epoch 2000.0)
Distance from Sol: 8.601 light-years (2.637 parsecs)
"

    (4)

    ````


    Download StarData3.mw

     

     

     

     

    I'd like to pay attention to an article J, B. van den Berg and J.-P. Lessard, Notices of the AMS, October 2015, p. 1057-1063.  We know numerous  applications of CASes to algebra. The authors present such  applications to dynamics. It would be interesting and useful to obtain  opinions of Maple experts on this topic.

    Here is its introduction:

    "Nonlinear dynamics shape the world around us, from the harmonious movements of celestial bod-
    ies,  via  the  swirling  motions  in  fluid  flows,  to the  complicated  biochemistry  in  the  living  cell.
    Mathematically  these  beautiful  phenomena  are modeled by nonlinear dynamical systems, mainly
    in  the  form  of  ordinary  differential  equations (ODEs), partial differential equations (PDEs) and
    delay differential equations (DDEs). The presence of nonlinearities severely complicates the mathe-
    matical analysis of these dynamical systems, and the difficulties are even greater for PDEs and DDEs,
    which are naturally defined on infinite-dimensional function spaces. With the availability of powerful
    computers and sophisticated software, numerical simulations have quickly become the primary tool
    to study the models. However, while the pace of progress increases, one may ask: just how reliable
    are our computations? Even for finite-dimensional ODEs, this question naturally arises if the system
    under  study  is  chaotic,  as  small  differences  in initial conditions (such as those due to rounding
    errors  in  numerical  computations)  yield  wildly diverging outcomes. These issues have motivated
    the development of the field of rigorous numerics in dynamics"

    As the year draws to a close, we start looking forward to a new year and a new release of Maple. With every new release comes many new features and updates to explore.

    We are looking for several new beta testers with a good working knowledge of Maple; We need your input, your ideas, and your experience with our products to help us improve the software and get it ready for general release.

    There are many benefits to becoming a beta tester:

    • You’ll get to use the new software before anyone else does.
    • You’ll help us make our software better in ways that work for you.
    • Your suggestions could determine the future direction of the software.
    • You’ll get feedback right from the development team.

    If you are interested in becoming a beta tester for the next version of Maple, please email: beta (at) maplesoft.com for more information.

    The well known William Lowell Putnam Mathematical Competition (76th edition)  took place this month.
    Here is a Maple approach for two of the problems.

    1. For each real number x, 0 <= x < 1, let f(x) be the sum of  1/2^n  where n runs through all positive integers for which floor(n*x) is even.
    Find the infimum of  f.
    (Putnam 2015, A4 problem)

    f:=proc(x,N:=100)
    local n, s:=0;
    for n to N do
      if type(floor(n*x),even) then s:=s+2^(-n) fi;
      #if floor(n*x) mod 2 = 0  then s:=s+2^(-n) fi;
    od;
    evalf(s);
    #s
    end;

    plot(f, 0..0.9999);

     

    min([seq(f(t), t=0.. 0.998,0.0001)]);

            0.5714285714

    identify(%);

    So, the infimum is 4/7.
    Of course, this is not a rigorous solution, even if the result is correct. But it is a valuable hint.
    I am not sure if in the near future, a CAS will be able to provide acceptable solutions for such problems.

    2. If the function f  is three times differentiable and  has at least five distinct real zeros,
    then f + 6f' + 12f'' + 8f''' has at least two distinct real zeros.
    (Putnam 2015, B1 problem)

    restart;
    F := f + 6*D(f) + 12*(D@@2)(f) + 8*(D@@3)(f);

    dsolve(F(x)=u(x),f(x));

    We are sugested to consider

    g:=f(x)*exp(x/2):
    g3:=diff(g, x$3);

    simplify(g3*8*exp(-x/2));

    So, F(x) = k(x) * g3 = k(x) * g'''
    g  has 5 distinct zeros implies g''' and hence F have 5-3=2 distinct zeros, q.e.d.

     

    A modified version of John May's modification of Bruce Char's animated Christmas tree, using some Maple 2015 features to automatically scale the 3D plot and automatically play the animation.

    I went with the viewpoint option, and removed the blinking lights. In the worksheet the tree shows as scaled larger. Perhaps it could be a submission to walkingrandomly.

    bchartree1.mw

    The CIELAB perceptual model of human vision can be used to predict the color of a wavelength in sRGB. I found the CIEDE2000 corrections to hue, chroma, and lighness were required to get the right values in the blue to violet region. The CIEDE2000 results seem pretty close to what I see looking through a diffraction grating considering I have no way of knowing how my eyes are adapted.

    Use the new, faster  version. It can run in under 1 minute;

    nprocWavelength_Color_CIEDE2000.mw   and  WtoC_data.xlsx

    You will need the data for the color matching functions in the WtoC Excel File. The data directory can now be controlled in the mw file.

     

    This is a post that I wrote for the Altair Innovation Intelligence blog.

    I have a grudging respect for Victorian engineers. Isambard Kingdom Brunel, for example, designed bridges, steam ships and railway stations with nothing but intellectual flair, hand-calculations and painstakingly crafted schematics. His notebooks are digitally preserved, and make for fascinating reading for anyone with an interest in the history of engineering.

    His notebooks have several characteristics.

    • Equations are written in natural math notation
    • Text and diagrams are freely mixed with calculations
    • Calculation flow is clear and well-structured

    Hand calculations mix equations, text and diagrams.

     

    Engineers still use paper for quick calculations and analyses, but how would Brunel have calculated the shape of the Clifton Suspension Bridge or the dimensions of its chain links if he worked today?

    If computational support is needed, engineers often choose spreadsheets. They’re ubiquitous, and the barrier to entry is low. It’s just too easy to fire-up a spreadsheet and do a few simple design calculations.

     Spreadsheets are difficult to debug, validate and extend.

     

    Spreadsheets are great at manipulating tabular data. I use them for tracking expenses and budgeting.

    However, the very design of spreadsheets encourages the propagation of errors in equation-oriented engineering calculations

    • Results are difficult to validate because equations are hidden and written in programming notation
    • You’re often jumping about from one cell to another in a different part of the worksheet, with no clear visual roadmap to signpost the flow of a calculation

    For these limitations alone, I doubt if Brunel would have used a spreadsheet.

    Technology has now evolved to the point where an engineer can reproduce the design metaphor of Brunel’s paper notebooks in software – a freeform mix of calculations, text, drawings and equations in an electronic notebook. A number of these tools are available (including Maple, available via the APA website).

     Modern calculation tools reproduce the design metaphor of hand calculations.

     

    Additionally, these modern software tools can do math that is improbably difficult to do by hand (for example, FFTs, matrix computation and optimization) and connect to CAD packages.

    For example, Brunel could have designed the chain links on the Clifton Suspension Bridge, and updated the dimensions of a CAD diagram, while still maintaining the readability of hand calculations, all from the same electronic notebook.

    That seems like a smarter choice.

    Would I go back to the physical notebooks that Brunel diligently filled with hand calculations? Given the scrawl that I call my handwriting, probably not.

    I am learning to use maple for my notes preparation for the subject Finite Element Analysis. It is interesting to know that how often we blame maple or computer for the silly mistakes we made in our commands and expect the exact answers. I have used a small file and find it easy to analyse my mistakes fatser. If we make a small mistake in a big file, it not only gives us problem finding our mistakes, it leads to more mistakes in other parts as well. A command working in one document need not necessarily work the same way in other document.

    I have made my first document and people will come with suggestions to make appropriate modifications in the various sections to improve my knowledge on maple as well as the subject.

    Download FINITE_ELEMENT_ANALYSIS.mw

    Ramakrishnan V

    rukmini_ramki@hotmail.com

    Most of the tags in this question example are rediculous "the, you, is, and, help, how," etc... .  I tried editing them but I cannot save tags to remove junk tags.  Above all, the most important tag to the question Poincare is not there.  This specific issue is for the recent question  http://mapleprimes.com/questions/207460-Poincare-Section

     

     

    Since we’re almost at the end of the year, I thought it would be interesting to look back at our most popular webinars for academics in 2015. I found that they fell into one of two categories: live streaming webinars featuring Dr. Robert Lopez and Maple how-to tutorials.  (If you missed the live presentation, you can watch the recordings of all these webinars below.)

    The first and second most popular webinar were, unsurprisingly, both of the live streaming webinars that featured Dr. Robert Lopez (Emeritus Professor at Rose Hulman Institute of Technology and Maple Fellow at Maplesoft). These webinars were streamed live to an audience and allowed many people to get their first glimpse of the man behind the Clickable Calculus series and Teaching Concepts with Maple:

    1.       Eigenpairs Enlivened

    In this webinar, Dr. Robert Lopez demonstrates how Maple can enhance the task of teaching the eigenpair concept, and shows how Maple bridges the gap between the concept and the algorithms by which students are expected to practice finding eigenpairs.

    2.       Resequencing Concepts and Skills via Maple's Clickable

    In this webinar, Dr. Lopez presents examples of what "resequencing" looks like when implemented with Maple's point-and-click syntax-free paradigm. Not only can Maple be used to elucidate the concept, but in addition, it can be used to illustrate and implement the manipulations that ultimately the student must master.

    The next three were all brief webinars on how to complete specific tasks in Maple 2015. Just under a dozen of these were created in 2015 and they were all quite popular, but these three stood out above the rest:

    3.       Working with Data Sets in Maple

    This video walks through examples of working with several types of data in Maple, including visualizing stock and commodity data, forecasting future temperatures using weather data, and analyzing macroeconomic data, such as employment statistics, GDP and other economic indicators.

    4.       Custom Color Schemes in Maple

    This webinar provides an overview of the colorscheme option for coloring surfaces, curves and collections of points in Maple, including how to color with gradients, according to function value or point position. Examples of how the colorscheme option is used with various commands from the Maple library are also demonstrated.

     5.       Working with Units in Maple

    Maple 2015 allows for more fluid and natural interaction with units. This webinar provides an overview of the new unit formatting controls and new Temperature object, and demonstrates how to compute with units and tolerances.

    Are there any topics you’d like to see Robert cover in upcoming webinars? Or, any Maple how-to videos you think would be a helpful addition to our library? Let us know in the comments below!

    Kim

    As some of you have previously mentioned, we have seen an increase in the amount of spam on MaplePrimes over the past few months. We recently took steps to improve it in a recent update that has so far proven helpful, and have also increased our behind-the-scenes efforts to proactively remove and block spam accounts.

    Today we made a couple of additional minor changes to member profiles that should help further. Specifically, members can no longer enter HTML tags in the biography, 'technical interests/fields', and 'other interests' sections within their profiles. Spammers were co-opting these areas to create links back to their sites, and it is our hope that MaplePrimes will become much less attractive to them now that the capability has been removed.

    In addition, we de-activated a large number of accounts (with 0 reputation) that were using these fields for spam. Prior to taking this action, we reviewed the records we were deactivating, and did not see any evidence of legitimate members. However, there is a small chance that we blocked a legitimate account in the process of doing this. If this has occurred to you, please accept my apologies and send an e-mail to custservice@maplesoft.com and we will reactivate it quickly.

     

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