Consider, just a test example, the following list of lists of positive integers ordered ascendingly

L := [[1,2,7,12],[3,4,5,6],[1,2,5,9]];

I would like this list of lists ordered so that [1,2,5,9] precedes [1,2,7,12], because 5 < 7 (the first two elements being equal), and [1,2,7,12] precedes [3,4,5,6], because 1 < 3. I think you see the general scheme. That can be achieved with the following code:

with(ListTools):
swapLists := proc(L1::'list'(posint),L2::'list'(posint))
   local L;
   L := MakeUnique(L1-L2);
   if L = [0] then
      false
   elif L[1] <> 0 then

In connection with setting attributes on Arrays, as discussed here, I have run into a problem which boils down to the following: why does the code (which is only for test purposes)

p1 := proc(x,y)
   table(['x' = x,'y' = y])
end proc:
p2 := proc()
   local x,y;
   x,y := 1,2;
   table(['x' = x,'y' = y])
end proc:
p1(1,2);
p2();

produce two different outputs; the former, p1, evaluates 'x' and 'y', even though they are surrounded by unevaluation quotes, while the latter, p2, does not?

When using matrix with real (non integers) coefficients, maple does significant mistakes. Does somebody knows why?

I present the following:

[> restart;
[> a1:= foo = bar;
                             a1 := foo = bar
[> a2:= blam = foo = bar;
Error, `=` unexpected
[> a3:= blam = a1;
                       a3 := blam = (foo = bar)

The fact that the definition of a2 (correctly) throws an error and the definition of a3 does not can lead to some odd errors down the way. I disagree with Maple's choice not to say that the assignment of a3 is in error.

Ok, I'm now using maple 11, previously i was using maple 8. I'm trying to define a coordinate array, in this case i do this by setting the array, Coords:=({x,y,z}); however maple 11 now seems to change the ordering of the array. giving as output: Coords := {y, z, x} How do I make it stay as x,y,z????? Why would it do this??

Maplesoft just launched a brand new section to our website, the Maple T.A. Content Center. This is a new site that contains great content that can be used in Maple T.A. The content center co-exists alongside the Maple Application Center as a dedicated location for Maple T.A. Content.

You will find content that can be dropped in for Drill & Practice, Homework and Testing, all in different subject areas. You can also access Maple T.A. Tips & Techniques as well as Maple T.A. Documentation & How-Tos.

Users can also submit their own content to the database. Once you have submitted content, it is easy for you to edit the content through the new My Content page which also lists any Maple Applications or Books that you have contributed to Maplesoft.com.

Please visit the Content Center at www.maplesoft.com/tacontent and leave your comments here.

The student is supposed to use the logistic differential equation given to them (with carrying capacity .52e12), dsolve() the differential equation with a specific initial condition, and then calculate the population at 3 different times. Notice what happens:

[> restart;
[> my_deq := (diff(P(t), t))/P(t) = .789*(1-P(t)/(.52*10^12));

                   d
                   -- P(t)
                   dt                               -11
         my_deq := ------- = 0.789 - 0.1517307692 10    P(t)
                    P(t)

[> dsolve({my_deq,P(2290)=.83*10^10});

Why is it not possible to edit the root-post of a thread before anyone has replied to it? I ask, of course, because sometimes, despite proofreading, I overlook typos or bad grammar (being Danish, the latter is quite often a bit difficult to avoid), or because I simply want to add additional material that comes to mind after having posted.

In the column "Replies" of "all recent posts" it is indicated whether there have been submitted new posts to the topic since the last login/visit. Could such a thing be implemented also for the "my recent posts"? If affirmative, I think it would make it easier not to overlook any post which needed ones attention.

I am working on a new package, called "Spacetime", which I intend should be able to treat any physical field, either tensorial (integer-valued spin, like the photon) or spinorial (half-integer valued spin, like the electron) on any curved Riemannian manifold (gravity, according to Einstein). Anyway, for the Maple specific part: I have decided to implement these general fields as multi-dimensional Arrays, analogous to the older package "Gravitation", which "Spacetime" is intended to replace. They may have some symmetries and/or antisymmetries among their various indices. That part, that is, setting up the appropiate indexing functions, even in the general case, I have solved.

I submitted, to Maplesoft, a document that describes several bugs in Maple 11.01. A copy of the document is available here: http://www.informath.org/maple/Problems-1101.mw (Note: the document is about 900 kB, which is currently too large for MaplePrimes upload.)

The following system of equations can be solved by Maple 9.5 and Maple 10, but either takes a long time in Maple 11 or else simply won't solve. Is anyone else experiencing problems with the solve command? Earlier I noticed that Maple 11 was returning duplicates in solutions, but this is more serious. We tried this system on Maple 9.5 and Maple 10, and it solves easily, but on two computers with Maple 11, in classic worksheet mode, minutes went by with no solution. {2*a[2,6]*a[2,9]-2*a[2,8]*a[2,9], 2*a[1,5]*a[3,1]+2*a[1,7]*a[3,1], 2*a[2,6]*a[3,4]-2*a[2,8]*a[3,4], 2*a[1,5]*a[2,1]+2*a[1,7]*

Under Maple 10, the command densityplot(10-x-y, x = 0 .. 3, y = -x .. x, scaling = constrained, colorstyle = HUE, style = patchnogrid)

Got a Maple application that will knock our socks off? Something with cool images, elegant math, or just a great introduction to using Differential Equations? We want to see it! Maplesoft is running a contest to find the best new Maple applications out there. To enter, simply contribute your document on the Maple Application Center, including the line “The Maplesoft Great Application Contest” in the Comments box. (However, all submissions to the Maple Application Center will automatically be considered.) Submissions must be received by January 15, 2008. One grand prize will be awarded, consisting of one of:

Apple iPod Nano Canon Powershot digital camera A460 4.5” (114mm) reflector telescope Deluxe wooden chess set

Runner-up winners will receive their choice of:

Maplesoft laser pointer pen Maplesoft mug Maplesoft hat

Submission Guidelines: Award-winning applications will:

Be created in Maple 11 Make use of the new Maple “Document Interface” including 2-D math input Be well-formatted and laid out; for instance, you could use tables to format your document

They may additionally have some of the following characteristics:

Use Embedded Components Use the “Point-and-Click” paradigm

Make sure your application includes instructions. Some things to consider while writing the instructions are whether the document can be modified and re-executed, if a user will interact with the document using Embedded Components, and whether a user needs to follow instructions to use interactive tools. The following Maple documents are good examples of appropriate applications:

“Just Move it Over There, Dear!” Classroom Tips and Techniques: Eigenvalue Problems for ODEs - Part 3 Double Wishbone Suspension

Hi, is the JavaViewLib package 3.22 running with Maple 11? After: libname := "/home_zam/plch/maple/JavaViewLib", libname: with(JavaViewLib): (this works fine in Maple 10) I received: Warning, system/ssystem calls have been disabled in the options dialog. Any suggestions? With best regards. Roman