Dr. Jean-Michel Collard

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19 years, 12 days
Western suburb of Paris, France
-Differential Topology -Quantum Cosmology PhD in Mathematics MSc in Astrophysics That's all Folkx ("Looney Tunes")

MaplePrimes Activity

These are replies submitted by Jean-Michel

Your first paper is trivial.

As to the second paper it's hard and who would want

to program this in Maple. It's a question of time...14 pages.


A := Statistics:-Sample(Normal(0, 1), [2500, 2500]);
U, S, Vt := SingularValues(A, output = ['U', 'S', 'Vt']);
Norm(((U . (DiagonalMatrix(S))) . Vt) - A);
                   2.13709377885201723 10   

Read 2.....^-11



I have no crash here on a AMD Ryzen Threadripper with windows 10 proi 21H1.

But I don't have the fujll result.

Hello moderators,

The link in the post has not be removed.The URL works perferctly.

And I am not sure that ALL material on Research Gate is copyrighted.

Anyway I don't know how to solve the problem posted by the OP.




Thank you so much indeed Acer.

(I can't send you for Maple 2020 because I never keep previous versions of Maple.

I wrote down the result on a sheet of paper)


Hello Acer,

I apologize for my approxmatif English :)

I just wanted to ask : why after the release of a new Maple version the ratio nonCUDA/CUDA diminishes.

No more, no less :)

Brrrr I was quite good in English in my youth.Geez

Happily in Mathematics the words are almost the same.

@Carl Love 


I think that your last post is a bit ...rough.

I am not used to "rough" messages!

I am an old retired mathematician...this means that I presumably am not silly.

Your little program is particulary wise!

So I won't use uour e-mail address as to this subject. I will shut on it.

However try my things with 'in' and you SHALL have an...ERROR.

So think a bit more on 'diff'.

For me this discussion ies closed.

Kind regards,


@Carl Love

Bonsoir Carl .

I suppose you are allowed to see the e-mails addresses of MaplePrimes users.

I would like you to pick my email. This way it would be possible for me to send e-mail about your solution

at what I posted.

This may be very boring for this "forum".

Kind regards,


Thank you Tom and Carl I got it this time.Many thankx.

For example for INT this doesn't work and I have an error message..

*I* missed something and my GI were really garbage!

It's akmost 3 in the morning here and I hope I have been clear.

Take care you two.




Hello Tom,

Thankx for your reply.

Well...I EXPECT an ERROR when inputing this GI.

Of course this is NOT a bug of Maple,that I understand.

I suspect this is a misconception of Maple. This really should spits an ERROR !

Best Tom.


The philosophy of GIGO (Garbage In Garbage Out) is very simple :

I input to Maple a GI but Maple spits out a GO !

As I said in my previous post Maple should have returned an error.

No Carl it was not necessary to open a new thread for a simple question : I was talking about the Physics package at some point so I thought that I could ask this question.




Hello all ,

- Carl :

When I was a student (a long time ago) I had lectures on "Logique et théories axiomatiques" (No need to translate I think)

so I know what is a "libre" (free) variable and a "liée" (bound) Variable :)

I also had lectures on Category Theory ..It was mainly the book "Categories for the working mathematician" (Springer-Verlag).Excellent book.

Anyway this was a long time ago and I passed my Ph.D on differential geometry/topology . (Exotic Spheres)

Now what I do with Maple : I mainly use the "packages" DG, GrTensor,Physics.

Si I am not an expert on the other things of Maple even after 30 years...

There are a *lot* of things I don't know in Maple...

Now : Maple *should* return an error when I do stupid things like (x+y=1)' ==> 1=0 .

Now I work on Minimal Surfaces  and Cosmology when I have time.

For short thank you Carl!


-Edgardo :

Any idea to implement 2-spinors in the Physics pckage ?


Best to all.

Thank you *very* much Kitonium.


Hello Kitonium,

Thank you but this is not exactly what I'm looking for.

What you wrote is the link to all my "questions".

With that I can't reply to Carl.




Thnks Kitonim now I can sleep on my two ears :-)

Best to all

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