JacquesC

Prof. Jacques Carette

2401 Reputation

17 Badges

20 years, 85 days
McMaster University
Professor or university staff
Hamilton, Ontario, Canada

Social Networks and Content at Maplesoft.com

From a Maple perspective: I first started using it in 1985 (it was Maple 4.0, but I still have a Maple 3.3 manual!). Worked as a Maple tutor in 1987. Joined the company in 1991 as the sole GUI developer and wrote the first Windows version of Maple (for Windows 3.0). Founded the Math group in 1992. Worked remotely from France (still in Math, hosted by the ALGO project) from fall 1993 to summer 1996 where I did my PhD in complex dynamics in Orsay. Soon after I returned to Ontario, I became the Manager of the Math Group, which I grew from 2 people to 12 in 2.5 years. Got "promoted" into project management (for Maple 6, the last of the releases which allowed a lot of backward incompatibilities, aka the last time that design mistakes from the past were allowed to be fixed), and then moved on to an ill-fated web project (it was 1999 after all). After that, worked on coordinating the output from the (many!) research labs Maplesoft then worked with, as well as some Maple design and coding (inert form, the box model for Maplets, some aspects of MathML, context menus, a prototype compiler, and more), as well as some of the initial work on MapleNet. In 2002, an opportunity came up for a faculty position, which I took. After many years of being confronted with Maple weaknesses, I got a number of ideas of how I would go about 'doing better' -- but these ideas required a radical change of architecture, which I could not do within Maplesoft. I have been working on producing a 'better' system ever since.

MaplePrimes Activity


These are replies submitted by JacquesC

Correct, I had to use some human ingenuity there. That type of ``reasoning'' is not (currently?) in Maple, as far as I know. Maple knows a lot of math, some simple, some extremely advanced. However, there is still a lot more math out there; and some of that math which Maple does not know is covered in first and second year courses at university.
Correct, I had to use some human ingenuity there. That type of ``reasoning'' is not (currently?) in Maple, as far as I know. Maple knows a lot of math, some simple, some extremely advanced. However, there is still a lot more math out there; and some of that math which Maple does not know is covered in first and second year courses at university.
Without more details, I don't think anyone will really be able to help you. I definitely suggest that you pack up your worksheet and send it off to support@maplesoft.com, to ensure that the developers have a record of this bug so that they can fix it. If you post your worksheet here, people on primes might be able to find a workaround for you.
As I said before, with is of no use in this context. march returns a list (of lists) with names, timestamp, start and length information. You only really need the name. libname := "C:\\MyDocs\\MyMaple\\Mylib" , libname; interface(verboseproc=3); lst := map[2](op, 1, "MyLib"); loaded := map(proc(x) local y; y := convert(x[1..-3],'name'); eval(y,2) end, lst); and then you can print any of the results in 'loaded'.
As I said before, with is of no use in this context. march returns a list (of lists) with names, timestamp, start and length information. You only really need the name. libname := "C:\\MyDocs\\MyMaple\\Mylib" , libname; interface(verboseproc=3); lst := map[2](op, 1, "MyLib"); loaded := map(proc(x) local y; y := convert(x[1..-3],'name'); eval(y,2) end, lst); and then you can print any of the results in 'loaded'.
Only has 2 lines, 2 numerical evaluations (at least, that is what I see). Did you mean to post something longer? Also, notice how `Bessel/realJI` is invoked inside an evalf call? That means that the code is actually in `evalf/Bessel/realJI`, which does 'print'.
Only has 2 lines, 2 numerical evaluations (at least, that is what I see). Did you mean to post something longer? Also, notice how `Bessel/realJI` is invoked inside an evalf call? That means that the code is actually in `evalf/Bessel/realJI`, which does 'print'.
Is this herd available somewhere? If I have some time one day, I'll try to derive where that matrix recursion comes from. Yes, it indeed has to come from the quadratic transformation of the hypergeometric, but that's still pretty vague!
This is the kind of stuff where Maple is a real life-saver. Most mortals cannot manipulate that many symbols (correctly) in finite time! Question: do you have any intuition at all for where that 3-variable recurrence comes from? [I did not look at Forrey's article]. The inner 2-variable coupled recurrence is rather intriguing.
Give us an example! The answer is completely different depending on the details.
Maple is very well equipped with lots of functions to deal with polynomials over finite fields. See ?modp as one entry point.
Maple is very well equipped with lots of functions to deal with polynomials over finite fields. See ?modp as one entry point.
In any case, the book's derivation of the solution is rather sloppy, since you don't quite have 2 arbitrary functions -- Maple's solution takes all 3 equations into consideration properly. You are correct that the integral does represent a function of x and y. In your worksheet, here are two ways to get different solutions: 1) simplest -- make all arbitrary functions 0
> value(eval(opl, {_F1=0, _F2=0}));
            {Ay(x, y, z) = -a z, Ax(x, y, z) = b z - c y}
2) get the book solution:
> value(eval(subs({_F1=((x,y)->:-`*`(c,x)), _F2=0},opl)));

            {Ay(x, y, z) = -a z + c x, Ax(x, y, z) = b z}
Interestingly, the 'right' way to do 2 above brings out a bug in Maple:
> value(eval(opl, {_F1=((x,y)->c*x), _F2=0}));
Error, (in depends/internal) improper op or subscript selector
And it also brings out the issue that using with(VectorCalculus) is a mixed blessing, since that shadows the normal *, so that the ugly :-`*` must be used instead!
In any case, the book's derivation of the solution is rather sloppy, since you don't quite have 2 arbitrary functions -- Maple's solution takes all 3 equations into consideration properly. You are correct that the integral does represent a function of x and y. In your worksheet, here are two ways to get different solutions: 1) simplest -- make all arbitrary functions 0
> value(eval(opl, {_F1=0, _F2=0}));
            {Ay(x, y, z) = -a z, Ax(x, y, z) = b z - c y}
2) get the book solution:
> value(eval(subs({_F1=((x,y)->:-`*`(c,x)), _F2=0},opl)));

            {Ay(x, y, z) = -a z + c x, Ax(x, y, z) = b z}
Interestingly, the 'right' way to do 2 above brings out a bug in Maple:
> value(eval(opl, {_F1=((x,y)->c*x), _F2=0}));
Error, (in depends/internal) improper op or subscript selector
And it also brings out the issue that using with(VectorCalculus) is a mixed blessing, since that shadows the normal *, so that the ugly :-`*` must be used instead!
Thanks. And that probably means I am spending too much time on here instead of doing something else (like writing more computer algebra papers!).
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