MaplePrimes Commons General Technical Discussions

The primary forum for technical discussions.

Create a new Post in this category

Consider a signal which is a real sine series, f(x)=2*sin(2*Pi*x) + 5*sin(2*Pi*6*x) + 9*sin(2*Pi*11*x).

Let F(w) be its Fourier transform. Answer F(w) is purely complex and expressed in terms of symbol Dirac.

Maple "plot" fails.

Plots of impulse trains like F(w)=sqrt(Pi)*I*(2*Dirac(w-Pi)+4*Dirac(w-4*Pi)) involve user intervention. Maple won't plot such expressions, because they are DISTRIBUTIONS (not FUNCTIONS).

Try plotting F(w) to see the engine's uninformative error message....

@Carl Love 

Same here, I've tested Opera and Firefox. I haven't bothered trying other browsers because if it doesn't work with Firefox, the most popular browser, it may be considered broken.

But I can branch out alright...

Editing:

@Carl Love 

Earlier this afternoon we made an update to MaplePrimes to introduce some new features and to squash a few bugs.

The primary purpose of the update was to improve the context around how replies and answers are entered on MaplePrimes. The most significant change you will notice here is that submission/edit boxes now appear inline  under the specific message you are replying to, instead of at the bottom of each page.

Other improvements include:

Dear Maple Users

I am mainly in favor of the new rules concerning subscripts. Using Ctrl+-- (double underscore) it is pretty straight forward to get a literal subscript and it displays much better in the palette Variables than was the case i Maple 16. Also the purple coloring of a variable containing a literal subscript makes sense, because it can be distinguished from the usual subscript (now Ctrl+shift+-). Good that you can remove the coloring in the View Menu (Atomic Variables...

I'm pleased to announce that Maplesoft is working with the team at DigiArea, Inc. to further develop and enhance their Integrated Development Environment (IDE) for Maple. When we're done, the IDE will be distributed under the Maplesoft brand, and available for purchase through our Web Store.

The IDE doesn't replace Maple's current user interface, but is instead a separate, specialized environment for developing medium- to large-scale Maple libraries. It includes tools...

Introducing Maple 17...

March 13 2013 laurent 805 Maple 17
16
12

Every year at Maplesoft, we continue to pursue our mission of making powerful computational mathematics easily accessible within a friendly environment. Maple 17 is no exception: Hundreds of new algorithms, from differential equations to statistics to signal processing, continue to keep Maple ahead of the curve. At the same time, a wealth...

The application center has undergone some changes.  I usually like to see if things are working properly.

There are currently problems with searching maplesim models.  Doing an advanced search under maplesim5 does not bring up all maplesim 5 models, such as

- Flow dynamics in liquid connected tanks
- Double glazed windows


The next issue is with regards to phantom applications that are there but not linked.  For example:  Advanced...

Mathematica 9 was just released Nov 28 which caused me, of course, to have a look to see what wolfram has done in way of comparing itself to maple. 

Perhaps we can discuss, compare, debunk, clarify some of their claims or perhaps dismiss the results altogether

Here is one speed comparison chart I came across.  Is it relavent?  It shows Maple 16 as the worst performer.

 

I have found very little help about the Generate command of the RandomTools package.

I also have minor gripes about the syntax. And what better way to deal with these than to voice them?

This is how I was able to generate random lists and random Matrices.

A list of 10 random integers between 1 and 100:

L := RandomTools:-Generate(list(integer(range=1..100),10));

      L := [47, 8, 46, 44, 9, 77, 59, 16, 1, 70]

 

As many of you know now the MRB constant = sum((-1)^n*(n^(1/n)-1),n=1..infinity).

Here are some equations involving various forms of that summation.

The first one involves convergent series and is too obvious. The others involve divergent series.

The last two, however, are new!

 

Let c=MRB constant and a, c~, x, and y = any number.

 

sum((-1)^n*(c~*n^(1/n)-c~),n=1..infinity)= c*c~.

evalf(sum((-1)^n*(n^(1/n)-a),n=1..infinity)) gives c-1/2*(1-a).

evalf(sum((-1)^n*(x*n^(1/n)+y*n),n=1..infinity)) gives (c-1/2)*x-1/4*y.

And it appears that

evalf(sum((-1)^n*(x*n^(1/n)-a),n=1..infinity)) gives (c - 1/2)*x + 1/2*a.

Just happen to come accross this wikiVS page of Maple vs Mathematica. 
http://www.wikivs.com/wiki/Maple_vs_Mathematica

I find it heavily biased towards Mathematica. 

The version 16 of Maple does not know the function "pow", it is replaced by "power". Nevertheless, the codegen[optimize] procedure still generates it!  Moreower, it's not optimal even to write poser(..., 1/2)  as, most probably, the function sqrt must run faster. 

  Here's an example: (the function being optimized just contains some nested square roots)

> iang10 := [codegen[optimize](Re(int11), tryhard)];
[ 2 t17

There are two interesting threads about definite integration on the usenet group comp.soft-sys.math.maple posted in the past few days.

The first thread is more about the wrong result coming out of Maple's int command when computing via its `MeijerG` method. Motivating examples there include

int(cos(t)/(1+t^k), t=-infinity..infinity);      # for k=10,12,14,...

The poster demonstrates using residues to obtain a terse result.

In the second thread the poster examines the ideas that the solutions involving RootOfs (as returned by the `ftoc` method) may suffer from numerical difficulties during floating-point evaluation and are unnecessarily complicated when re-expressed in terms of more standard functions (ie. allvalues, then simplification...).

For those interested, an existing `contour` method exists within `int`. It is not very strong however. One can examine its source using commands such as,

showstat(`int/definite/contour`);

showstat(`int/definite/contour/def1`);

etc.

See also Methods of contour integration on wikipedia.

Recently, I published the following paper.

"Calibration of a radiocarbon age", Nonlinear Processes in Geophysics, 19: 345–350 (2012).

The paper explains that all radiocarbon dates are inaccurate, due to an error in the handling of the statistics.

The paper has a Supplement, which includes a program to do the statistics correctly:

3 4 5 6 7 8 9 Last Page 5 of 72