Earlier today, we posted an update to MaplePrimes that introduces some improvements, and also addresses a few issues. The most significant & noticeable improvements are speed related, and the performance of virtually every function/page on MaplePrimes has been improved dramatically.  The average increase is approximately 2x, but some pages (for example, Recent Questions or Unanswered Questions) benefit from much greater increases!

Other issues/enhancements include:

• There was a problem where MaplePrimes would occasionally send multiple notification messages when a single reply/comment/answer was added to a thread that you are subscribed to. This no longer occurs.
  
  
• MaplePrimes has been added as a clickable option under 'products' when asking a question or creating a post, and MaplePrimes-related topics are now grouped together.
  
  
• The lag between when a new thread is created and when it appears in the right-hand side bar (this lag was often multiple minutes) has been eliminated. 
   
• We added a data-integrity restriction such that if an answer or a reply has been added to a message, that original message can no longer be deleted. Formerly, the original author was able to remove their post, and subsequently all related comments, at any time.

There were a variety of smaller issues corrected as well.

We hit a couple of small bumps in the road during the implementation of the update (for example, there was a temporary issue where replies or answers didn't work), but we believe these have been taken care of. If you encounter any additional issues, please let us know.

We hope that these enhancements and fixes continue to make MaplePrimes more enjoyable to use, and I'm looking forward to your feedback!

Bryon

I can't post any Replies or Answers. It acts like they are being posted, but they just disappear. I've tried both in IE and Firefox.

I would like to Maple 18 has tabs and dropdown menus NO. So in this way the locations of the applications would be

Is there a specific reason why this web site (Mapleprime) is so slow? I have visited this number of times, since the early days it opened, and it is still as slow as the first day it was launched.

Just wondering. I think this extreme slowness of MaplePrime does not reflect good on Maple itself.

In addition, the line below the title of topics and questions, is always cut off in the middle. Fonts are not good, and the overall site, and entering text and code is very awkward to use.

Voting is open for the next individual prize to be awarded as part of the Möbius App Challenge.  The winner will receive an iPad Prize Pack! 

Here are the finalist Apps:

• Parameterized Curves
• ODE Systems

http://lib.freescienceengineering.org/search.php?search_type=magic&search_text=maple&submit=Dig+for

Bug in type(HFloat(-infinity),  pos_infinity). Negative infinity is incorrectly recognized as positive one:

s:=HFloat(-infinity);
                   HFloat(-infinity)

type(s, neg_infinity);
type(s, pos_infinity); # bug
                    ...

Hi
Just finished updating the comparison between Maple 17.02 and Mathematica 9.01 in solving the 1390 Ordinary Differential Equations (ODEs) of Kamke's book:

• Mathematica solved 80% in 7 hours and 8 minutes
   
• Maple solved 97.5% in 43 minutes

While trying to solve the whole set, Mathematica hanged with 90 of these ODEs while Maple hanged with 6 ODEs. A pdf with a summarizing table and all the details is linked below

It is also relevant here that Maple's dsolve has close to half of its code implementing more modern methods, not found in Kamke, illustrated in the Maple 'what's new in DEs' help pages of the last 10 releases; for these other kinds of equations the difference is more impressive. I'll see to prepare another post about that.

Edgardo S. Cheb-Terrab
Physics, Maplesoft

Comparison_Kamke.pdf

The question was "Let X be the random variable uniformly distributed in the disk centered at the origin O(0,0) with radius 1 and let Y be the random variable uniformly distributed in the square having its vertices A(6,-1), B(9,-2), C(8,-5), and E(5,-4). What is the PDF of the distance between X and Y? Is it possible to find that with Maple?"
Having a long think about the topic, I draw the conclusion that the exact closed form of the PDF/CDF, even the one can be found, would be useless because of its complexity.
Thus, an approximate formula for the CDF/PDF under consideration is a proper way. That formula can be derived in such a way. First,rotating the picture, we may consider the square having its sides horizontal or vertical: K((1/5)*sqrt(1410)-(1/2)*sqrt(10),1/sqrt(10)), L((1/5)*sqrt(1410)+(1/2)*sqrt(10),1/sqrt(10), M((1/5)*sqrt(1410)+(1/2)*sqrt(10),1/sqrt(10)-sqrt(10)), Q((1/5)*sqrt(1410)-(1/2)*sqrt(10),1/sqrt(10)-sqrt(10)). The geometry behind that is omitted.
We randomly choose a point P1 belonging to the square [-1,1] x [-1.1]. If the one belongs to the disk {(x,y):x^2+y^2 <=1}, then we randomly choose a point P2 from the square [K,L] x [Q,L]. Next, we calculate the distance between P1 and P2 (The  LinearAlgebra[Norm] command http://www.maplesoft.com/support/help/Maple/view.aspx?path=LinearAlgebra/Norm is used to this end.) and add it to the set S.This is repeated 2*10^4 times.

Converting S to an Array A, we constuct the empirical distribution X by A and find its mean mu and standard deviation sigma.

7.67568900820260

1.029831470

Let us compare the obtained empirical distribution and the normal distribution with the parameters mu and sigma.

The plot suggests a good fit between these. However, it is only semblance. Applying the Kolmogorov-Smirnov test (for example, see  http://www.mapleprimes.com/posts/119903-The-KolmogorovSmirnov-Test
), we  calculate

and

3.32619143372726

while the critical value equals 1.358098639 at the level 0.05. Thus, the hypothesis about the concordance should be rejected.

Also we draw the approximation to the PDF:

CDF.mw

This blog post is a response to a post on MaplePrimes.  MaplePrimes user wkehowski asked how the Task Model could be used to filter combinations.  The basic problem is formalated like this:  We want a function, I'll call it FilterComb, that accepts positive integers...

Himmelblau.mw

     On the basis of Dragнilev method…

     Is there anyone interested in the algorithm to reduce the distance between the points of the given constraints? The algorithm is adapted for use in R ^ n. This is an example of its work on the surface:  
f = - (x1 ^ 2 x2-.3) ^ 2 - (x1 x2 ^ 2-.7) ^ 2 - 5;  

     Approximate description of the algorithm in pictures.

I have located a claimed webpage http://www.advanpix.com/2013/10/03/advanpix-vs-maple-sparse-solvers-comparison/ that shows Advanpix doing sparse matricies much faster than Maple.

The slowness is usually the result of poor coding or someone not well versed in Maple software. 

Anyone care to comment on the times?  I am sure the presented code there can be improved.

There seems to be patterns for sin(10^-k) for rational k;

Here we have the "floats."

n sin(10^(-n-1/2))

1 0.03161750640

2 0.003162272390

3 0.0003162277607

4 0.00003162277660

5 0.000003162277660

6 0.0000003162277660

7 0.00000003162277660

More later on using the mantissa. You're welcome to join me.

I define a partial repeating decimal as shown in the following example: if you have the decimal expansion 0.1728394877777777777777777777771939374652819101093837... 7 is called a partial repeating decimal.  

Back in 2000 I noticed a pattern in the decimal expansions of sin(10^-n) for growing n. Here is table of some integer n:

n                sin(10^-n)

1 9.98334166*10^-2

Back in 2000 I published A034948, A036663, and A036664 in Sloane's Integer Sequences, now OEIS.

But today I decided to find the exact values of some such quotients.

1/9801=0.repeating(000

100010203040506070809101112131415161718192021222324252627282930313233