Here is a simple bug:

If I define a function f via

>f:=x->solve(-x*(x+1)+y^(2/x),y);

I can plot(f(x), x=0.2..5) and evaluate f(3) but plot(f,0.2..5) yields an error message ( wrong argument  (f) in plot) and f(1.5) crashes Maple 12–connection to kernel lost.

If I define the function using fsolve or using unapply as in
> g:=unapply(exp((1/2)*ln(x^2+x)*x),x);

I can plot(g,0.2..5) or plot(g(x),x=0.2..5) or evaluate g(1.5) without problems.
 

Any idea whee the bug is?

 

This is something I produced for my Calculus students.  It is based on some actual research in Biology by Larry Dill of Simon Fraser University, showing that the escape response of the Zebra Danio, a small tropical fish, is triggered when the rate of change of the visual angle of a potential predator becomes too large (see ugrad.math.ubc.ca/coursedoc/math102/keshet.notes/chapter11Notes.pdf, section 11.2).
Here's my Maple document.

What are some good 3rd party add-ons for maple? 

Maple Advisor Database?  it's a little dated but I think a nice addition.  or Aladjevs library for Maple 2.2013 ? - what does this really add to Maple that it doesn't already have? 

Any comments on those or some other good suggestions?

(As perhaps many of you do?) I really enjoy the webcomic xkcd. In a fit of silliness I decided to write my latest Maplesoft blog post about velociraptor math... :)  Click here if you're interested.

Stephanie
Maplesoft

I recently came across a Probability and Statistics - Explorations with Maple book by Karian and Tanis.  It mentioned something about a stats package.

It seems that most of the stats package commands are mostly incorporated into newer maple versions. 

However some commands from the stats package seem to be better.  For example

Mean([x,3,1+x])  produces an error with the Statistics package in Maple where using Mean from the Stats package of Karian and Tanis produces a result. 

Hi, i am trying to find cosets of S_3 in Maple. I have done this so far: > restart; > with(group); > S_3 := permgroup(3, {[[1, 2]], [[1, 2, 3]], [[2, 3]], [[1, 3]], [[1, 3, 2]]}); permgroup(3, {[[1, 2]], [[1, 2, 3]], [[2, 3]], [[1, 3]], [[1, 3, 2]]}) > grouporder(S[3], ident); Error, (in group:-grouporder) expecting a permgroup or a grelgroup, but received S[3] > Group order should be 6 (which is 3!) but for some reason it does not work. Also I am getting an error message when I try to find cosets of S_3. > ident := permgroup*(3, {[]}); > cosets(S_3, ident);

If I highlight some text in the first line of a document and then wish to highlight text of the same color on the next line, and if the highlight color touches the one above in any way then a whole block is extended and highlighted for both lines.  

However it seems to be okay if different highlight colors are used.

I have developed a fairly complicated (by my standards) Maple routine that makes heavy use (again by my standards) of the numeric methods dverk78 and rkf45. Recently I posted about differences I seemed to be seeing between running this on Linux and on windows. I was in error; the difference seems to be between Maple 13 and Maple 11. Maple 13 gives the same answers on Linux and on Windows.

My son Eric began high school this year (grade 9) and a marvelous thing happened. In my previous posts, I lamented that I was generally unable to spark in him an interest in math but something changed this year. The first sign was his first math test given within the first two weeks of the new year. It was an assessment of sorts to see who knows what, and he scored 90%. Although it was a review of basic arithmetic with complicated fractions, order of operations, and such, this was the first time he had ever ranked within the top few of his class in math. Fast forward a few days. He came up to me with a large grin and said “Dad, you’re in my math text book!” Actually it wasn’t me but there was an indirect reference to Maple in one of the later chapters of the book that he was perusing out of curiosity (another good sign). “This is your stuff isn’t it?” With tears welling up inside, I proudly answered “yes.”

A favorite diversion of mine (and of many around the Maplesoft office) is xkcd. Its author, Randall Munroe, bills it as “a webcomic of romance, sarcasm, math, and language.” Since 2005, he’s been entertaining many self-proclaimed geeks with his unique and slightly skewed jokes on technology, computer science, mathematics, and relationships.

I really like the post in which a substitute teacher – hm, Mr. Munroe......

I'll implement Jacques' suggestion that the discussion about parsers should be in a separate topic.

 

I don't really have anything prepared for today, so I'd like to ask you a few questions about the posts I've made so far.  My goal for this blog was to give typical Maple programmers the information they needed to start trying parallel programming. 

1. My posts progressed fairly quickly, building up to the the Task Programming Model. Did I move too quickly?  Were there topics that I did not explain well enough or that you felt needed more explaination?
2. As my goal was to present the Task Programming Model, I skipped a deeper explaination of Threads:-Create style of programming.    Would you like to know more about that type of low level threaded programming?
3. Most of the examples I used were artifical ones that illustrated the points I was trying to make.  Would you have prefered real world examples instead?
4. Did reading my posts get you to actually try writing a parallel algorithm?  If yes, did you succeed?  If no, why not?
5. Was the formatting ok, especially the code?  Each post included an worksheet containing the examples from the post so I did not worry too much about ease of copy and paste.
6. What else would you like to know about?  I am definitely planning a post on GPU computing, but since it is not really a Maple topic I delayed it till after I am finished with the Maple topics.

Any other feedback you would like to provide would also be appreciated, although I'd like to keep focused on the topics discussed in my blog, and less about Maple in general.

Does Maple 13 still have strange behaviours with empty sums like M12?

  interface(version);
  Classic Worksheet Interface, Maple 12.02, Windows, Dec 10 2008 Build ID 377066

  #Sum(t^j*(z-a)^(-2*n+j)/j!,j = 0 .. -1+n); eval(%, n=1);
  #S:=Sum(t^j*(z-a)^(-2+j)/j!,j = 0 .. 0);
  S:=Sum(1,j = 0 .. 0);
  value(S);
  #subs(Sum = add, S); value(%);
  #eval(S, Sum = add);
  #eval(S, Sum = sum);

I have constructed a Maple routine which makes multiple calls to the dsolve numeric methods rkf45 and dverk78. I have been running on Windows Vista. Recently I began experimenting with Kubuntu Linux, thinking this might run faster. I was surprised to see that the same routine with the same numeric input gives different results depending on whether it is run on Kubuntu or Windows.