@Alejandro Jakubi 

Indeed, very interesting, thanks a lot for the pointers Alejandro. I remember reading one of those exchanges way back when. So the idea has been around for a while (10, 20 years?). Opening up the code or parts of the code, formally and officially, would be a radical step, but on balance I think it would benefit MapleSoft, if only in terms of advertising value, but a step into the unknown is always a delicate one to take...

@Alejandro Jakubi 

thanks that's an interesting discussion you had there.

if it's possible, it will be done, and if it's impossible it will take a little longer?

-- some famous quote, but I can't remember the author, just a joke --

only someone with a valid Maple license would have an incentive to undertake such a project, and that's a far smaller number than the freeware community, so in this sense the Maple project is less easily "decentralizable"...

I'm thinking about the success of Google and their smartphone Android platform --- it's hard to beat a community as large as the freeware community when it comes to innovation, maybe Maple could release some of its code, the stuff that pretty much any math software does nowadays, and reserve secrecy for the more advanced stuff, the toolboxes, the ODEs that only Maple can solve, and so on. A simple test would be: if you can do it with Scilab, let it be freeware. This could give birth to a MapleLite that, if I'm right about the kind of software the academic geeks like, would be probably quite similar to Classic Maple.

@Alejandro Jakubi 

of course it's a matter of degree, what I meant by "centralized" is that, as far as I know, the main Maple products are a proprietary code and not open source, which makes it impossible for anyone other than MapleSoft to write up a worksheet-only-classic-feel-but-up-to-date Maple 15.

> It is ashamed that we have such bifurcation: document/worksheet, 2D/1D input, standard/classic.

yes, I'm in complete agreement here.

The way I see it: if you have a decentralized system, in the sense of many similar software versions competing, then users will decide what they want, and it's quite possible to have several versions coexist (as did Neanderthals and CroMagnon for a while), and this is very much happening with linux distros, some diverge slightly, e.g. ubuntu/kubuntu and that's fine because it's freeware and open, impopular ideas naturally die out (Darwin).

But if you have a centralized system, as here with MapleSoft, then you need to make choices at the top, select an approach and philosophy and spend the resources on it, rather than dilute your effort into competing projects. And while classic and standard coexisted for a while, symptomatic of a lack of decision perhaps, now it has been made clear that the standard and document approach are favoured by the developers, hence my transition towards soft that's more like classic than like standard...

And, side remark, on my Windows 7-64bits, Maple 14 classic does NOT work (if the worksheet has plots, it crashes when you try to make the plots and at the same time permanently deletes the bit of code that comes after the plot)  (I made that remark a few months ago on mapleprimes but someone called it a myth, but it's not a myth for me and I tested on 3 different machines) (I now use standard as a result, it was a total pain to convert the worksheets by the way).

thanks acer, yes I've done this on occasions, now your comment is useful, what if I deem it so useful that I'd wish to upvote it? I can't right now, unless it gets converted into an "answer," for which I'd have to flag it, ask for it to be converted, but wait perhaps you don't want your comment to be upvoted in this particular instance? we could have several exchanges about this to see how we all feel about it, etc. ... what a complicated system. The way I'd go about this myself is: either you can upvote everything or you can upvote nothing...

my understanding is that the classic worksheet is no longer maintained, that is a real shame because I so much prefer its default behavior to that of the standard worksheet. I've learned to use the standard worksheet to mimick the classic behavior to some extent, but what annoys me the most is the loading time, often I want to open 30 worksheets in succession to quickly check what's inside, easy with classic, a total nightmare with standard... as a result I've recently shifted some of my activities to other software, which happen to be freeware, the whole "document" concept of Maple is just not for me...

sounds like a good idea, yes Alejandro the current system leaves much to be desired...

I use the mapleprimes archives a lot (usually by googling site:mapleprimes.com), I often find answers there, and I often find I'd like to "upvote" these, to point them out to others, to "unbury" them from the depths of the archives, but all too often they are not "upvotable" because they are "comments" and not "answers" ...

I don't find it all that useful to distinguish "answers" and "comments"...

I've experienced this too, what I do is: in the google search window

mysearchterms site:http://www.mapleprimes.com

hope this helps.

> Using that the two mixed partials w.r.t. x and y are equal you can write down a condition for solving the system

Oh that's very useful, thanks A LOT Preben.

On the other hand I'm a little sad: I don't see any "solvability" condition that matches my modeling constraints...

> Using that the two mixed partials w.r.t. x and y are equal you can write down a condition for solving the system

Oh that's very useful, thanks A LOT Preben.

On the other hand I'm a little sad: I don't see any "solvability" condition that matches my modeling constraints...

nice post, thanks, very useful to have all these tips in one place.

On gem 1: that's why I use LaTeX/PSTricks to label my plots. Once you have a system going it's pretty efficient.

On gem 2: that's not so much using Maple as Maple using you! It would be nice, though presumably a gigantic task, to have an option like, say, "diff(expr,x,suggest)" which would return several forms of the derivative taken from a stored table and from which you could select...

@Robert Israel 

Thanks again Robert, fantastic, I'm ready to race. I've already done a few warm-up laps --- it all seems to work.

@Robert Israel 

Thanks again Robert, fantastic, I'm ready to race. I've already done a few warm-up laps --- it all seems to work.

How to go from the set of permutations of n natural numbers to the generator matrix...

In the case of 5 cars, the generator matrix would be 120*120,

with(combinat):
numbperm([1,2,3,4,5]);
                              120

In generating the matrix one would need to assign a state to each one of the 5! permutations:
s:=permute([1,2,3,4,5]);
and use that to form the matrix...

I haven't found anything online with ready-made methods so far, the closest thing I've seen is this (top of page 378), on "random ladders":

http://mathdl.maa.org/images/upload_library/22/Polya/07468342.di020754.02p0120e.pdf

stuck here at this time.

How to go from the set of permutations of n natural numbers to the generator matrix...

In the case of 5 cars, the generator matrix would be 120*120,

with(combinat):
numbperm([1,2,3,4,5]);
                              120

In generating the matrix one would need to assign a state to each one of the 5! permutations:
s:=permute([1,2,3,4,5]);
and use that to form the matrix...

I haven't found anything online with ready-made methods so far, the closest thing I've seen is this (top of page 378), on "random ladders":

http://mathdl.maa.org/images/upload_library/22/Polya/07468342.di020754.02p0120e.pdf

stuck here at this time.