Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

How I can plot a volumetric body with the coordinates provided in the text file attachment?

after finding the geometry curve I want to find the curve that passes through the middle source.

1.txt

I recently answered a question concerning the Lane-Emden equation (see here LaneEmden) where the main topic was about finding its numerical solution.

The generic form of the Lane-Emden equation with parameter n is

LaneEmden := n -> (Diff(xi^2*(Diff(theta(xi), xi)), xi)) = -theta(xi)^n * xi^2

      d   /  2 / d            \\             n   2
n -> ---- |xi  |---- theta(xi)|| = -theta(xi)  xi 
      dxi \    \ dxi          //                  


I have just realized that I missed a "small" point in the original question: the OP ( @shashi598 ) wrote
"[...] Maple never comes out of evaluating [the] analytical solution when n=5 [...] ".
The important point here is that this solution (at least for some initial conditions) is known and simple (in the sense it doen't involve any special function).

So I tried for a few hours to verify this claim, and ended wondering myself if it might not be right?

Could you please tell me (I guess @shashi598 would be interested too in your return) if the differential equation LaneEmden(5) can be solved formally?
TIA.

Emden_equation.mw


EDITED:
After a little research it seems that very specigic method are used to build the analytic solution of the LaneEmden(n) (n not equal to 0, 1 and 5): serie expansions, homotopy, Adomian decomposition for instance.
I wasn't capable to find how the solution for LaneEmden(5) have been got for the first time (iseems to be atthe end of the 19th century).

How to apply the following relationship in maple commands? In this physics this relation it's utilized in effective field theory

Where can I find a tutor on Maples ??? I need a tutor on maple i am on graduate engineering  contat me anyone can help 

We just switched to a new Antivirus program (Bitdefender), and we are getting a bunch of security warnings because of outdated software.

I do have  a couple of those for my PC, e.g. some regarding Apache. I don't have Apache installed on my PC, but I think Maple does use it.

So I wonder which policy Maple has regarding updating its open source libraries.

A quick review on Maple Help - copyright information shows a couple of Open Source licenses code which seems to be delivered in old versions.

Bitdefender classifies them with a high security risk.

Hello sir

I am new to here

I am not familear with maple can i solve the pde in maple software and get the plots and tabular values which are mentioned in the below given pdf

The final equation (12-19) of the pdf to solve and get the plots like below mentioned figure number

Figure 4,17 and 23 one sample graphs 

With table 2 values. Basha-2023-Keller-box-computation-for-entropy

I heared about maple recently in reseach gate. It is friendly user.

Please tell me how to get the above mentiond values and plots.

There are two opposing commands remove and select in Maple. According to the main help page, StringTools:-RegSplit effectively implements the removal (i.e., capturing substrings that does not match the given pattern), but as regards extracting the matching parts of the input string (e.g., this example from MatLab), where is the command to carry out the selection?
At present I can do something like 

use StringTools in RegFilter := (p::string, s::string) -> select[2](RegMatch, sprintf("^%s$", p), (op@NGrams)~(s, [`$`](Length(s)))) end:
RegFilter("a.++b", "aabbbaaabb");
 = 
 ["aab", "abb", "aab", "abb", "aabb", "abbb", "aaab", "aabb", 

   "aabbb", "aaabb", "abbbaaab", "aabbbaaab", "abbbaaabb", 

   "aabbbaaabb"]


Nevertheless, there exist at least two disadvantages to it.

This is essentially equivalent to letting the matcher keeps starting at the same position until no more new matches are found, while sometimes one may just need the matcher to continue the shortest-match testing at the character following the last matched substring after finding a match:

For instance, there should be three flags in “RegFilter("a.+?b", "aabbbaaabb", 'overlapped'=⁇);”: 
⒈“["aab", "aaab"]” (selection with no overlap), 
⒉“["aab", "abb", "aaab", "aab", "abb"]” ( with partial overlaps), and 
⒊“["aab", "aabb", "aabbb", "aabbbaaab", "aabbbaaabb", "abb", "abbb", "abbbaaab", "abbbaaabb", "aaab", "aaabb", "aab", "aabb", "abb"]” ( with full overlaps). 

Unfortunately, the  above can only handle the last mode.

Another disadvantage is its inefficiency. Considering the following regular expression which matchs email-like strings

sample := Import("https://github.com/mariomka/regex-benchmark/raw/optimized/input-text.txt"): # lengthy 
re := "[a-zA-Z_0-9\\.+-]+@[a-zA-Z_0-9\\.-]+\\.[a-zA-Z_0-9\\.-]+":
time[real]((remnants := StringTools:-RegSplit(re, sample)));
 = 
                             3.157

So Maple is capable of completing this removal within 4 seconds, yet if I execute the analogous

timelimit(60, time[real](RegFilter(re, sample))); 

Maple will end up running out of memory.

In view of these, where is the generic StringTools:-RegFilter functionality? Or can we construct those matched cases from  and the original text?

Dear maple users,

i want to solve these 4 difference scheme equations to calculate the values of U,V,C,T and plot the graphs i verse U by fixing the values

i:=1,Sc:=2,Gr:=5,Gc:=10,DX:=0.02;DR:=0.2,Dt:=:=0.01:m:=7.44,7.88 where ,j=0..5;

eq1[i,j,m]:=(1/(4*DX))*(U[i, j-1,m+1]-U[i-1, j-1,m+1]+U[i,j,m+1]-U[i-1, j,m+1]- U[i-1, j-1,m]+U[i, j,m]-U[i-1, j,m])+(1/(2*DR))*(V[i, j,m+1]-V[i, j-1,m+1]+V[i, j,m]-V[i, j-1,m])+(1/(1+(j-1)*DR))*(V[i, j,m+1]):

eq2[i,j,m]:=(1/Dt)*(U[i, j,m+1]-U[i, j,m])+(U[i, j,m]/(2*DX))*(U[i, j,m+1]-U[i-1, j,m+1]+U[i, j,m]-U[i-1, j,m])+(V[i, j,m]/(4*DR))*(U[i, j+1,m+1]-U[i, j-1,m+1]+U[i, j+1,m]-U[i, j-1,m])=(Gr/2)*(T[i, j,m+1]+T[i, j,m])+(Gc/2)*(C[i, j,m+1]+C[i, j,m])+(1/(2*(DR)^2))*(U[i, j-1,m+1]-2*U[i, j,m+1]+U[i, j+1,m+1]+U[i, j-1,m]-2*U[i, j,m]+U[i, j+1,m])+(1/(4*DR*(1+(j-1)*DR)))*(U[i, j+1,m+1]-U[i, j-1,m+1]+U[i, j+1,m]-U[i, j-1,m]):

eq3[i,j,m]:=(1/Dt)*(T[i, j,m+1]-T[i, j,m])+(U[i, j,m]/(2*DX))*(T[i, j,m+1]-T[i-1, j,m+1]+T[i, j,m]-T[i-1, j,m])+(V[i, j,m]/(4*DR))*(T[i, j-1,m+1]-T[i, j-1,m+1]+T[i, j+1,m]-T[i, j-1,m])=(1/(2*Pr*(DR)^2))*(T[i, j-1,m+1]-2*T[i, j,m+1]+T[i, j+1,m+1]+T[i, j-1,m]-2*T[i, j,m]+T[i, j+1,m])+(1/(4*Pr*DR*(1+(j-1)*DR)))*(T[i, j+1,m+1]-T[i, j-1,m+1]+T[i, j+1,m]-T[i, j-1,m]):
eq4[i,j,m]:=(1/Dt)*(C[i, j,m+1]-C[i, j,m])+(U[i, j,m]/(2*DX))*(C[i, j,m+1]-C[i-1, j,m+1]+C[i, j,m]-C[i-1, j,m])+(V[i, j,m]/(4*DR))*(C[i, j+1,m+1]-C[i, j-1,m+1]+C[i, j+1,m]-C[i, j-1,m])=(1/(2*Sc*(DR)^2))*(C[i, j-1,m+1]-2*C[i, j,m+1]+C[i, j+1,m+1]+C[i, j-1,m]-2*C[i, j,m]+C[i, j+1,m])+(1/(4*Sc*DR*(1+(j-1)*DR)))*(C[i, j+1,m+1]-C[i, j-1,m+1]+C[i, j+1,m]-C[i, j-1,m]):


For several hours I experience difficulties to upload a mw file (file LaneEmdenNumeric.mw to answer this question).

Given the error message I get

I thought it was a general technical problem.

But then I realized that this file ColumnSorting_4.mw , for instance, could be uploaded.

Nevertheless, as soon as I try to upload LaneEmdenNumeric.mw I get the error displayed above and it becomes impossible to upload any other file, even ColumnSorting_4.mw.

Does someone has any idea about what's going on?
TIA

For the record, LaneEmdenNumeric.mw contains nothing special that could prevent its uploading.
This file can be uploaded here  DropBox  (replace the txt extension by mw before opening it with Maple).

integral of sqrt(sin(x)) is known to be as given in few place such as in here and other places.

Maple gives a result which is much more complicated (but also in terms of EllipticE special function). 

Could someone find a way to simplify it to the above answer and also to the same answer given by Mathematica?

int(sqrt(sin(x)),x)

Compare to 

Maple's result seems to be correct, as I plotted it and compared the smaller known resut. But I was not able to simplify it to obtain the smaller antiderivative.

Any tricks to do that?

Hi all

I need your advice on Maple usage after a long break. I installed Maple on my laptop and first of all tried to launch my old program. Surprisingly, the old file opened. While the core Maple functionality remained familiar, the user interface had undergone some changes.

Yet, I soon encountered challenges when attempting to perform even the simplest operations, like file browsing or text selection; the Maple Standard GUI seemed uncharacteristically sluggish.  I switched to Maple Input mode but it didn't help much. Are there ways to improve my experience with Maple? Is it caused by the outdated hardware?

My system:
Ubuntu 22.04.3 LTS
Dell Inc. Latitude 5510 (1TB SSD, 32GB RAM).

Maybe it works much better on Windows?

Thank you for any suggestions.

Modal Analysis is a very usefull feature. Only the animation window is sometimes too tiny.

How to enlarge this view and to pause the animation?

This seems to be a Maple plot window (a "Rotate the view" cursor is visible and the animation can be rotated). Are there any short cuts or functions keys to toggle plot view options?

Edit: Looks to my like a Maplet. Maybe a Maplet programmer can tell if that (what I am asking) is possible

Hi, 

Some of my maple documents contain data tables. 

When I want to view these documents with the maple cloud viewer, the data tables are invisible (the table is completely grayed out) and it is therefore impossible to change the values in this table. 

The table properties are such that it is enabled, visible and editable. 
Does anyone have an idea how to solve this problem? 
Thanks in advance. 

Whats the best way to let a Maple-Code run in webspace.

The Maple-Procedure gets some parameters from a mobile-App. Then doing calculations and giving back data as a file to the mobile app.

I have alomost decided for Deno which accepts Javascript. This is develeoped by Ryan Dahl who has also created Node.

Deno is more compact and very fast. So I when I use a deno server code  then I need the Maple-Code in language Javascript.

I have tried to translate some maple-subprocedures of my code with CodeGeneration but this is very restricted I think.

Thanks for ideas :)

Both, Maple and MapleSim in Versions from 2021 to 2023 do not start. A logfile is saved which starts as

# A fatal error has been detected by the Java Runtime Environment:

#

#  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x0000000000000000, pid=17256, tid=10520

#

# JRE version: OpenJDK Runtime Environment Temurin-19.0.1+10 (19.0.1+10) (build 19.0.1+10)

# Java VM: OpenJDK 64-Bit Server VM Temurin-19.0.1+10 (19.0.1+10, mixed mode, tiered, compressed oops, compressed class ptrs, g1 gc, windows-amd64)

# Problematic frame:

# C  0x0000000000000000

#

This only occurs when the notebook (on which the error occurs) is connected to the domain network. If the notebook is not connected, Maple and MapleSim can be started and will continue to run when the network is reconnected.

Has anybody seen this before or any ideas what this could be?

Edit: This all happened under Windows 10 on a notebook that has been running Maple for 3 years and only recently displayed this error.

Edit2: Connection via an USB doc which also connects to an external monitor.

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