In trying to evaluate the accuracy of an asymptotic approximation, I asked evalf to return the numerical value of the difference of two expressions.  It evaluated each expression but would not take their difference (see line 6).  Any idea what's going on?

Download asyapprox.mw

How do i plot / graph a limt? The plot must have a hole at 2 because it is undefined.

Download graph-a-limit.mw

the second ode is giving me zero also when we back to orginal under the condition by using them must the orginal ode be zero but i don't know where is mistake , when Orginal paper use some thing different but i think they must have same results i don't know i use them wrong i am not sure at here just , when U(xi)=y(z) in my mw

Download ode.mw

this is my first time something like that   coming up my equation after taking integral exponential coming up why?

g1.mw

the series is so complicated but have a strange pattern if you watch the index of parameter  they are not repeated 

Do you think the result of String(0.016)  should be "0.016"  instead of ".16e-1" ?

Any reason why it gives the second form and not the first?  Now have to keep using sprintf to force formating as decimal point. Is this documented somewhere? quick search did not find anything do far.

Maple 2024.2 on windows.

Download string_of_decimal_number.mw

I am calling a proc inside a module, where this module had local module variable initialized to false;

This works fine when calling the proc normally.

When calling it from Grid:-Run() it says it is not seeing the module local variable at all.

Why does this happen and is there a workaround this? Here a simple worksheet showing this.

I hope there is a way to make the proc inside the module see the local module variables when using it from Grid node. Otherwise, this whole thing will not work for me, as I have few variables initialized at modules level in number of places.

Download grid_with_module_local_variable_feb_7_2025.mw

Update 2/7/2025

I tried to change the access to the module local variables from the module local procs, by adding explicit A:- to each variable name where A here is the module name.

This works for normal calls, but not when using Grid to call the proc.

This workaround fail, it gives error that module does not export `%1`

May be I have to redo all my code not to use local module variables. But in some places I have to do this, in order to detect if something has happened before or not. I use module local variables to store state the presist after call is completed.

It looks like Grid is not meant to be used for calling proc() that uses/lives inside modules. But this makes Grid not very useful then for large application.

Download grid_with_module_local_variable_feb_7_2025_V2.mw

I also tried to make the module variable as export instead of local, and that also did not work. I am starting to run out of ideas what else to try...

Download grid_with_module_local_variable_feb_7_2025_V3.mw

Update

I think now that using module level local variables will not work with parallel processing anyway. It is like using global variable in parallel processing. Does not work without synchorization of access to this shared variable. 

So this means I have to change my code and not use any module local variables, and pass any information between functions via arguments only.

Using module local variable is more convenient, but I now realize this design is not good for parallel processing.  This means some code changes I have to do. 

On the positive side, I find using Grid can really speed things up. On some tests, up to 10 times faster. The larger the number of problems to process, the more speed up is gained.

So I think it is worth to rewrite my code and remove any use of local level module variables.

Update Feb 11, 2024

Found the solution!  With grid, one must pass in all variables that to be used on a node. So the above now becomes this

Download grid_with_module_V4_feb_11_2025.mw

Actually the above could be done easier this way. By passing in the name of the whole module A, now nodes are able to see all module A local vaiables. Like this

Download grid_with_module_V6_feb_11_2025.mw

And to be able to access global variables in another module from inside the worker module, we must pass the other module name. Here is an example

Download grid_with_module_V5_feb_11_2025.mw

The main point, if one is using modules with Grid, names of all modules to be accessed from a node need to be passed in in the Set call. Otherwise the node will not see them.

Update For the above method to work, all module variables to be accessed at node, have to export and not local.

Update 2/11/2025  4 AM

I think I'll give up on Grid. It is completely useless. I found out that I have to make all my modules proc's export now, even though they are only used in that one module, just in order to call them from same module when running in Grid node.

Otherwise, I have to list each proc name in each module and sub module in the Set command. This is ridiculous design. I have 5,000 proc's. I am not going to list them all each time.

Here is an example where a boo() is local proc to a module. But it is not called, because the proc is local.

Download calling_proc_in_module_V1.mw

To make it work, I have to make all my local proc export, and not only that, I have to call it using A:-boo() as well. So the above becomes

Download calling_proc_in_module_V2.mw

I am not going to edit 100,000 lines of Maple code and change all the procs to export and make sure each call have the fully qualified module name attched to it even though it is local to the module.

I will not use Grid. It simply does not work with modules. Maplesoft should fix Grid so code works as with minimal changes.

How i can get FN from N-soliton to FN for M-lump by applying long wave method and using limit How we can get the series of lump , there is some example for nowing how lump work like f[2] for 1 lump and f[4] for two lump and f[6] for 3 lump i, and also in last of work i showed the series of for n soliton which we can change it to m-lump  but i don't know how work and a[12] will change to b[12] by applying long wave method

m-lump.mw

Referring to the screenshots, "J" can be converted to "N m" in MF2024.1, but not in M2024.2.
Is this some sort of bug in M2024.2?

To select all pdf files in folder the command is

L1:=FileTools:-ListDirectory(currentdir(),'all','select'="*.pdf");

And to select all dvi files the command is 

 L2:=FileTools:-ListDirectory(currentdir(),'all','select'="*.dvi");

Is there a syntax to select both in one command? THis does not work as input to select must be string. It can not be list nor set.

  FileTools:-ListDirectory(currentdir(),'all','select'=["*.dvi","*.pdf"]);

So I end up doing

L1:=FileTools:-ListDirectory(currentdir(),'all','select'="*.pdf");
L2:=FileTools:-ListDirectory(currentdir(),'all','select'="*.dvi");
the_list := [ op(L1), op(L2) ];

If will be nice if Maple allows one to select based on different extensions in one command.  Imagine you have 5 different extensions to select. Now one has to issue 5 different commands, then collect all the 5 lists into one.

Download dsolve_problem.mw

Download liouville_reduced_2-2-2025_mprimes_vraag.mw

I read the install.html that is installed with Maple2024 and the instructions to increase stack and heap limits are definately outdated.

None of the files they list there for Linux even exists after the Maple2024 installation.

So where exactly can I set the stack and heap size limits on Linux,  as Maple give me stack and heap errors.

It been a while i try to figure out How they find dispersion parameter and phase shift i figure out how find dispersion in some of pde but some of them is not give me even dispresion parameter i don't know they wrong or i am , but for finding phase shift there is three cenarios, when we change pde to bilinear form we have linear term in bilinear form so after substitute in linear term f bilinear form we can get dispersion parameter which is a parameter beside (t) also we can generalized for all of solution by changing the number of parameter as mention in the paper, but for phase shift parameter i don't know how find it i must substitute our solution in linear term or whole  bilinear form of in first pde linear term i try all  but i don't know what is i did mistake the paper say put in pde but i think he mention the the bilinear form i did all part for one soliton is w[1] for 2soliton is w[2] file i just want find parameter a[12] in paper for 2-soliton eq(19)  then i will find for other just i need to find one of them, thanks for any help  in this topic .

I am trying to show that the eigenvalues of a matrix are described by my proposed formula. I managed to show this numerically, but I would like to show this symbolically. There are two issues here - the orders of the two lists are different, and the forms are different (sums of complex exponentials vs RootOfs). Any suggestions?

>  restart; >  with(LinearAlgebra): with(GraphTheory): with(plots): >  L:=9; Generate a matrix and its eigenvalues >  C := AdjacencyMatrix(CycleGraph(L, directed)): Id := IdentityMatrix(L): A := KroneckerProduct(C, Id) + KroneckerProduct(Id, C) + KroneckerProduct(C, C): evs := Eigenvalues(A, output = list): plotevs := complexplot(evs, style = point, color = blue, scaling = constrained): My guess as to their values >  evstheory:=[seq(seq(exp((2*Pi)*I*k/L) + exp((2*Pi)*I*m/L) + exp((2*Pi)*I*(m + k)/L), k = 0 .. L - 1), m = 0 .. L - 1)]: plotevstheory:=complexplot(evstheory, style = point, color = red, scaling = constrained): They look to be the same >  display(Array([plotevs,plotevstheory]));         Even showing they are the same numerically is nontrivial because the sorting is not consistent >  fnormal(sort(evalf(evs))-sort(evalf(evstheory))); This succeeds, so they are the same >  fnormal(sort(evalf[20](evs),key=evalf)-sort(evalf[20](evstheory),key=evalf)); What about symbolically? [Edit - only part of output shown] >  ans1:=simplify(sort(evs,key=evalf)-sort(evstheory,key=evalf)); >

Download verification.mw