MaplePrimes Commons General Technical Discussions

The primary forum for technical discussions.

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:

I guess there is a limit bug here somewhere.  With MultiSeries things are OK...

L:=(x*BesselI(k-1, x)+x*BesselI(k+1, x))*BesselI(-k, x);
L := (x BesselI(k - 1, x) + x BesselI(k + 1, x)) BesselI(-k, x)
simplify(limit(L,x=0)) assuming k>0;
0
with(MultiSeries): simplify(limit(L,x=0)) assuming k>0;
2 sin(Pi k)
-----------
Pi

BesselLimit.mw

This is a comment and warning to anyone in the United States using MapleTA 8. 

If you get login information using LDAP, MapleTA 8 gets the "employee number" from the LDAP data base  and displays it on the screen when a person is logged in.  After talking to our IT people, they acknowledge that this is a FERPA violation when using MapleTA in a lab where people can see screens of other people's computers.

Our IT people have contacted Maplesoft for...

MapleSim has seen a rapid evolution since its inception in 2008 as a multi-domain system-level modeling and simulation environment. Market response has been outstanding: Maplesoft has been working with an expanding list of key industry players such as AISIN AW Co., Ltd. and B&R,  while major customers like

Viewing an html application at the application center results in some problems which doesn't allow to view the application in it's html format.

I had responded to a maplesoft application where data to a .mw worksheet was no longer available and had asked them to find and fix it.

I would have hoped a response would have been put here to mapleprimes to find the data.  Unfotunately the data could not be found and the application was deleted from the application center. 

It was Analyzing Data files in Maple - Maple 10 and Maple Net - Nov 7, 2005

Here is the link http://www.maplesoft.com/applications/view.aspx?SID=1685 ...

After making a search for applications in the applications center, they are ordered in some crazy unknown way. 

They do not appear to be ordered alphabetically by author, nor by title and also they have no date published attached to the searched list. 

Searching for all titles by product Maple 16, we find that TEST APPLICATION created July 31 is actually listed behind Robert Lopez's Classroom Tips and Techniques: Slider-Control of Parameters in Numeric...

MapleSim now is in direct competition with Mathematica's System modeller.

I just found that out now, it could have been out for a while but they look similar.  Mathematica is already comparing it with MapleSim and essentially indicating that their modeller is superior.

Let's hear from the Maple crowd.  Is System Modeller better than MapleSim?

There is a flaw (bug) in the DEplot routine.  If you load the plottools package before using DEplot with the arrows=line option, the DEplot routine tries to use the line definition from the plottools package.  A worksheet illustrating this problem is below.

It appears the wikipedia entry for Maple (software) is deeply in need of an overhaul to reflect new graphic modifications and for better eye candy. 

Not that it really matters but the graphics there are rather primitive and outdated. 

When using "plotsetup(png,...)" the third rotational angle is ignored.  Attached are a worksheet and the corresponding three plots that demonstrate this bug.

The explosion of cloud this - cloud that, is rather obvious now.

 

SO, I decided to check-out the cloud feature to my Maple? One problem, I cannot see - what is in it?

  • Yes, I understand, you use the cloud palette in Maple.
  • It shows the group, who the document / notebook is from, what it's title is? And such.
  • _
  • BUT, is there a web page - listing? hidden somewhere, on MaplePrimes or someplace on Maplesoft's service? (

Some Maplesoft users have been receiving emails that indicate a new patch for Maple software is available. Recipients of this message receive an attachment called Maple_Patch.zip which they are asked to extract using the password MapleSecuirityUpdate1707. Please be advised that this patch did not originate from Maplesoft and should not be opened under any circumstances. Maplesoft is currently investigating further. Please contact

The MRB constant can be computed in Maple by evalf(sum((-1)^n*(n^(1/n)-1),n=1..infinity)).

On my laptop restart; st := time(); evalf(sum((-1)^n*(n^(1/n)-1), n = 1 .. infinity), 500); time()-st gives a timming of 37.908 seconds.

Using the procedure posted at the bottom of this message st := time(); A037077(500); time()-st gives a much faster timing of 1.903 seconds.

My fastest timing for 500 digits of MRB comes from my...

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