The question https://www.mapleprimes.com/questions/233780-Plot-Absolute-Advantage-Of-Option-A disappeared (I know since I answered today).

Why?

A have som problems when i Will save a project. It Will take 2-5 Minutes where my other freinds never Experince this? Also i have some problems when i pauses writing, when i take notes in class, it Will give me the loading circle on mac( iam using a MacBook Air 2018) 

i hope you Can help:)

thx

The two points on the sphere has radius r=1/2. So, the distance is 1.
The three points on the sphere has radius r=1/sqrt(3). So, all distances are 1.
The four points on the sphere has radius r=sqrt(6)/4. So, all distances are 1.
What is the smallest sphere radius for 5 points and above numbers?  

Find the smallest sphere radius and 3D position of each point.

Answer of smaller radius is better.

Tokoro.

Download 3D-4points.mw

Dear all

I know how can I use gauss seidel to solve a linear system.

But, how can we add chebychev acceleration.

Thank you 

hi 

hiiiiiiiiiii

i am working and modling on brushless motor for my project but when i run that i get this error and i can not fix that could you please help me. error is :

equation generation

(}),At offset 4370 in `:-2108.m`, unexpected DAG type: 0,125

every project  i run  has the same error 

@acer,
In the past, you had shown how to use take a given sparse A matrix and store the LU components and use the same factorization for multiple backsolves at https://www.mapleprimes.com/posts/41191-Solving-Sparse-Linear-Systems-In-Maple#comment200817

When PDEs are solved, we are calling the A matrix at every time step (with some discretizations in x) and the factorization is done and stored at every time step (this is time-consuming and memory-consuming). Is it possible to call UMFPACK using only the sparse storage and entries? The main routine seems to provide the option 

https://people.sc.fsu.edu/~jburkardt/f77_src/umfpack/umfpack.html

This would mean that the pattern is found only once for the Jacobian at t= 0, then only the non-zero sparse entries (vector/row, not a matrix) are updated at every time step.

To be clear, what I am asking for is create a random sparse matrix (say 4x4 or 10x10)
create a b Vector.

Solve AZ =b with method = SparseDirect. (This should internally create and store R, CC, X as at https://people.sc.fsu.edu/~jburkardt/f77_src/umfpack/umfpack.html)

Store R, CC, X and update only X for a different A matrix with the same sparsity pattern and solve for Z using stored (R, CC), and updated X.

which kind of input is DeepLearning:-Optimizer(GradientDescent()) suppose to take? Nummeric value or function?

I have an assignment for my class but I don't know how to get the answer without getting an error. Maple_2.mw
 

Download Maple_2.mw

Download greek-index.mw

windows 11 maple 2020 I can load other packages but cannot load the student packages

Session Save doesnt work:

DeepLearning:-Save("model.ckpt");  
Error, (in DeepLearning:-Save) format not supported

DeepLearning:-Save("model.h5");
Error, (in DeepLearning:-Save) format not supported

DeepLearning:-Save("model.keras");
Error, (in DeepLearning:-Save) format not supported
 

Which format is supported?

Why int gives this error? Is this a known problem?

Update

fyi, This is reported to Maplesoft.

Here is updated worksheet. The int() command does not generate the error the second time it used, but generates the error the very first time used. Hopefully will be fixed in 2022 Maple.
 

Download int_problem_feb_13_2022.mw

I am attempting to use the pdsolve function in Maple to explicitly solve a PDE which is basically a perturbation of the Laplace equation.  Nothing happens when I enter pdsolve, however, is this because a boundary condition is also needed to produce a solution?  The BC which I have is that f(x, y, z) goes to zero as sqrt(x^2 + y^2 + z^2) goes to infinity but I am not sure how to enter such a BC in Maple.

PDE := diff(diff(f(x, y, z), x), x) + diff(diff(f(x, y, z), y), y) + diff(diff(f(x, y, z), z), z) - exp(-t*exp(sqrt(x^2 + y^2 + z^2)))*(diff(diff(f(x, y, z), x), x) + diff(diff(f(x, y, z), y), y) + diff(diff(f(x, y, z), z), z))/(1 + m/(2*sqrt(x^2 + y^2 + z^2)))^4 = 3/2*exp(sqrt(x^2 + y^2 + z^2) - t*exp(sqrt(x^2 + y^2 + z^2)))*(diff(f(x, y, z), x)*tx/sqrt(x^2 + y^2 + z^2) + diff(f(x, y, z), y)*ty/sqrt(x^2 + y^2 + z^2) + diff(f(x, y, z), z)*tz/sqrt(x^2 + y^2 + z^2))/(1 + m/(2*sqrt(x^2 + y^2 + z^2)))^4;

pdsolve(PDE);

Hello, 

I am doing symbolic calculations of multi-body kinematics which involves more than 40-degrees of freedom. I built a module that will construct initial kinematic calculations and it finshes fairly quicly, (about 20s). When I want to retrieve these calculations, stored as proprties of the module, it takes really a long time, we are talking more than 30min. It's strange because these calcualtions were already made during the initalization of the module, I am just retriving them for the purpose of writing the symbolic results to a file to later be used in Matlab as functions. 

Any word of advice?

Thanks.