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.

what happened...

my god

I recently started experimenting with autocompile in Maple.

I must say that I am bit surprised by the difference in performance for different loops and procedures

depending of what type of notation you use. I have below presented 3 procedures that uses slightly

difference notation. We can see that the first procedure (iterating over list elements) is extremely slow in Maple.

The second procedure is faster but the third procedure (compiled, converted to C ) is fastest.

If I apply showstat to numtheory:-invphi I find that the last line is >remove(has,sort(map(convert,invrec(a,divlist),'`*`')),FAIL) What is invrec? >?invrec returns "no matches found". Thanks to anyone who can clear up this mystery for me! And why isn't it documented? So far as I can tell numtheory:-invphi works fine. --Edwin PS I am using Maple 13.0

pull up the context when we writing at the end of page.

 

When at the end of the page,the context we see is at the bottom of the screen,and I've always enter some "Enter" to get more blank area at the bottom for a good view of my context.

 

Anyone agree the suggestion?

Or how to reach the purpose,for my possible ignorance of ready-made features

In my previous posts I have discussed various difficulties encountered when writing parallel algorithms. At the end of the last post I concluded that the best way to solve some of these problems is to introduce a higher level programming model. This blog post will discuss the Task Programming Model, the high level parallel programming model introduced in Maple 13.

Maple returns a message saying that the use of global parameters in
the dsolve command is deprecated and will be eliminated in future
versions of Maple. One should use the parameters option instead.

I find entering parameters that way a bit clunky and prefer to use a
function instead. Is there some good reason to use the parameters
option? See below for a simple example.

Unless you’ve spent the past five years on an isolated island in the middle of the Pacific, you’ll have heard of Facebook and Twitter and LinkedIn and MySpace and Flickr. Social media sites: whether you love them, hate them, or just don’t get them, they’re going to be here for a while. If you’re like many of us, you may have a few accounts on these sites, whether you’re a power user or occasional dabbler. Social media allow us to re-connect with old friends and colleagues, share our thoughts – and photos, advertise, network... and generally waste time. :)