How do you convert this system of equations into matrix form? The decoupling process is performed.Convert the equations into photographs.fuxian1030.mw

Low power user (occasional) here! I would like to extract the parameters from a curve fit and assign to another variable?

What I do at the moment

u-> changecoords(u,[x,y,z],spherical_physics,[r,theta,phi]):
map(%,[x,y,z])
  [r cos(phi) sin(theta), r sin(phi) sin(theta), r cos(theta)]

Any other (preferably shorter) ways to look up transformations defined in ?coords

I am studying linear operators that have vanishing Nijenhuis Torsion, that is a (1-1) tensor L whose corresponding (1-2) tensor N given by a tensor equation of L (see attached) is identically zero.

I am new to maple, i have used it to plot vector fields and solve systems of equations in the past but i am unfamiliar with the DifferentialGeometry and Physics packages.

Attached is my best effort at solving this problem directly for a simple 2d case without the use of any packages and i am wondering if it is possible to do it all in one line without having to define tensor components one by one.

nijenhuis_torsion.mw

I just realized that voting for a deleted answer is possible. This does not make sense. Does an upvote also change the reputation?

You can try it in the answer to myself below, but please do not upvote permanetly for this question.
 

How can I use Maple to solve a system of nonlinear equations symbolically and display the steps in the solution?

Here are two systems over the reals:

The following results indicate that both and are satisfiable 

QuantifierElimination:-QuantifierEliminate(exists([s,q,r],sys__1));
                              true

QuantifierElimination:-QuantifierEliminate(exists([s,q,r],sys__1));
                              true

but RealDomain:-solve simply returns an empty list (that is, no solution exists) in both cases

RealDomain:-solve(sys__1,[q,s,r]); # ⟹ sys1 cannot be satisfied
                               []

RealDomain:-solve(sys__2,[q,s,r]); # ⟹ sys2 cannot be satisfied
                               []

As discussed in the previous problem, in contrast to using QuantifierElimination:-QuantifierEliminate, the use of RealDomain:-solve is unsafe. Nevertheless, the above output suggests that even the much-more-sophisticated QuantifierElimination:-QuantifierEliminate is still not always reliable (since the correct returnedvalue appears to be in lieu of ). So, what is the right command to handle polynomial systems over real domains in Maple? 

Can i get this ode in a "standardform"  ?

verg:= (-delta*eta^2 + alpha*eta)*diff(diff(U(xi), xi), xi) - U(xi)*(2*eta*gamma*theta*(delta*eta - alpha)*U(xi)^2 + eta^2*delta*k^2 + (-alpha*k^2 - 2*delta*k)*eta + 2*k*alpha + delta) = 0;

Since the puzzle task "A circle is to be disturbed ..." makes no fun, here is a Maple task:
The term to be simplified step by step:
(2+10/(3*sqrt(3)))^(1/3)+(2-10/(3*sqrt(3)))^(1/3)

A circle with radius r is given. The circle should be divided into three
parts of equal area such that the circumference of each part is equal to the circumference of the circle.
(Note: There are several solutions.)

I have learned that the SPECTRA.mla library can solve SDP problems. I have tried to download and use it, but I am still missing the FGb module

How can I resolve this issue on a Windows environment, beause I don't see install file for Windows, only MacOS and Linux:

• FGb page: https://www-polsys.lip6.fr/~jcf/FGb/FGb/index.html
• Spectra page: https://homepages.laas.fr/henrion/software/spectra/

We are working to obtain a fully symbolic dynamic model for a robot. 

Using the CPU (I9-12900K) and 128 GB of DDR5 RAM (5600 MHZ) did not compute a 7x7 Inverse of a symbolic matrix

Is is possible to exploit the CUDA functions to compute it on the GPU? I have a NVidia RTX A6000 (48 GB of DDR6 GPU memory)

I tried this: 

CUDA:-Enable(true)

CUDA: -MatrixInverse(D_Q):

But it does not use the GPU to compute this. 

Maybe I'm doing smth wrong. 

Thank you, 

Calin