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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  • I'd like to suggest another improvement to cut down on noise in the result of a Mapleprimes Search.

    At present, the appearance of a searched keyword in summary pages for tag hits causes those summary pages to be included in the search results. Maybe an example would help explain it:

    Do an internal Mapleprimes Search for the word convex. Some of the pages with "convex" in their title are included in the results (which is fine). But some of the...

    I recently noticed that the symbol font in my maplets was not appearing correctly when I ran them using Maple 13 or 14 on my Windows 7 laptop. Additional testing showed that while this was pretty standard on Windows 7, it happened on some, but not all, Windows XP systems.

    By a stroke of fortune, my local inquiries about this problem suggested that I look at the Clear Type effect that can produce sharper results, particularly on newer LCD displays.

    Before going into too many details, let's look at an example. Here's the code for a simple maplet:

    restart:
    with(Maplets[Elements]):with(Maplets[Tools]):
    StartEngine();

    alphabet := "abcdefghijklmnopqrstuvwxyz":

    TestFont:=Maplet(
      Window[mainWin](title="Font Test", [
        [ "The two lines of text should show the alphabet in the Times font and then\n the Symbol font, but sometimes the Symbol font is not correctly rendered." ],
        [ "Times ",    Label( alphabet, font=Font("Times",18) ) ],
        [ "Symbol",    Label( alphabet, font=Font("Symbol",18) ) ],
        [ Button( "Done", Shutdown() ) ],
        [ "Version: ", Label( convert(interface(version),string) ) ]
      ]
      )
    ):
    Maplets[Display]( TestFont );

    Copy these lines to a Maple worksheet (or document) and execute them, or save them to a text file with file extension .maplet, then double click on the file. The maplet should display two copies of the alphabet, the first with Times Roman font, the second with Symbol font. (The version of Maple running the maplet is given at the very bottom of the maplet.)

    If you are running Maple 12 or older, I expect you'll see two different versions of the alphabet, like this:

    If you are running Maple 14, I expect the line that should be in Symbol font will be in a poor quality Latin font, like this:

    I can't predict which outcome you will see if the maplet is run in Maple 13.

    What controls this behavior is the "effects" setting for the appearance settings for your display. If you are using the Clear Type effect, you will not see the Symbol font.

    This problem is appearing now because up until Windows 7, the ClearType effect was not the default.

    Along with the change in the default effect, the way in which users control the effect changed with the introduction of Windows 7.

    Prior to Windows 7, access the Properties popup by right-clicking on your desktop. Then select the Appearance tab and click on the Effects button. In the second dropdown menu you can choose either Standard or ClearType. To see the symbol font (in Maple 13 and later), make sure this is set to Standard.

    In Windows 7, go to the start menu and search for cttune.exe. Start the ClearType Text Tuner application. In the first popup window, be sure the Turn on ClearType box is unchecked. (For full instructions, including screenshots, please see http://www.sevenforums.com/tutorials/337-cleartype-text-tuner.html .)

    When this effect is toggled, the effect changes immediately.

    I can't call this a bug, but it is something that I think should be included somewhere in Maple's documentation.

    Thanks for listening, I hope this is of use to someone else

    A while back, someone asked me for a good way to plot a Klein Bottle in Maple. I didn't have a good answer at the time, but I recently stumbled upon the following, which does a pretty good job if you don't mind the use of Heaviside in the parameterization.

    plot3d(
    [4*(1-1/2*cos(u))*sin(v),
    6*cos(u)*(1+sin(u))+4*(1-1/2*cos(u))*(cos(u)*(1-Heaviside(u-Pi))+Heaviside(u-Pi))*cos(v+Pi*Heaviside(u-Pi)),

    In a previous post, I promised to write about testing the quality of pseudo-random number sequences.  I'll post later about some of the statistical tests often used, but I first wanted to mention a sort of practical test one can do. One of the many things you might want to do with pseudorandomly generated numbers is Monte Carlo integration/simulatation/etc.  As mentioned by acer in this comment, Monte Carlo integration can be shown to work better with some of the pseudorandom number generators (PRNGs) which are considered inferior in a statistical sense.  In this post, we will play with a simple Monte Carlo approximation of π.

    I would like to see a valid reason for having the thumbs down voting for an original first posted question.

    Thumbs down, because it's not a good question? (That's not a good reason)  Thumbs down because bad code? (but that would be cleared up in the answers)  Thumbs down because ...

    It's apparent the administrator will not get rid of the thumbs voting system (sigh).  As a compromise I would like to suggest as I have above, remove...

    There are two pieces of extended functionality that I quite often want from the Maple Compiler. The first (task A) is to be able to link in and use an arbitrary function from some other external ("3rd party") shared library, within my Compile'd Maple procedure. The second (task B) is to directly call the compiled Maple procedure from within some computational routine in a 3rd party shared library (which I would then access using define_external). This post is about the first of those, task A.

    I just updated MaplePrimes to have a Print-Specific CSS file that fixes a bug in Firefox that was stopping more than one page printing. This also improves the quality of printouts for all browsers because it removes the sidebar, footer and header links. It also extends the main content to take up the whole width of the page.

    You will only see this change when printing a page from Primes, it does not change the appearance of the site when browsing normally.

    A recent comment addition of mine adding comments (in parse lists) did not update the last action in the thread, there is a 3 hour difference.

    I get what appear to be redundant email notifications from MaplePrimes.  Possibly an email is sent whenever anything changes in a thread to which I have responded, however, I'd prefer to get emails only if a response has been edited or a new response added.  That is, I don't need an email for a thumbs up/down addition (if that is the cause). Could that be added as a configuration option?

    A user recently asked how to find the set of indices corresponding to a given value of a two-dimensional Array.

    There are several ways to handle this problem.  For  a single value, a simple scan through the Array suffices:

    FindIndices1 := proc(A :: Array, val)
    local i,j,irng,jrng;
        (irng,jrng) := rtable_dims(A);
        {seq(seq(`if`(A[i,j]=val, [i,j], NULL), i=irng), j=jrng)};
    end proc:

    With a multi-core machine, the ...

    The hardest and/or most important part of answering a question is making sure the real question is understood. The July 1, 2010 question Using fsolve with a dispersion relation posted to MaplePrimes seemed to be about obtaining a numeric solution of an equation. Turns out it was more a question about the behavior of an implicit function.

    I recently celebrated my 10-year anniversary at Maplesoft. I've enjoyed my time here, working with a terrific group of colleagues, and I hope to be here for many more years to come. Part of the satisfaction comes from being able to interact with this wonderful user community.

    I also celebrated the 20th anniversary of the plot code, parts of which I've had the pleasure of maintaining and improving over the past 10 years. Actually, I believe it is closer to 25 years old...

    We need an area to create polling questions on this forum. 

    I find it very odd that this forum which is not very graphic intensive runs so slowly.  It runs like there's animated ads running in the background slowing things down, but this is a text forum with the odd graphic in the threads but hardly anything else.  I can't see why it can't work so much faster.

    Why must one have high speed and the latest browser for this site to work marginally well?  Load times for the home page should load almost instantly, on...

    The MRB constant is defined at http://mathworld.wolfram.com/MRBConstant.html.

    On about Dec 31, 1998 I computed 1 digit of the MRB constant with my TI-92's, by adding 1-sqrt(2)+3^(1/3)-4^(1/4) as far as I could. That first digit by the way is just 0.

    On Jan 11, 1999 I computed 3 digits of the MRB constant with the Inverse Symbolic Calculator.

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