Below is a simple demonstration of something that I am very confused about in another worksheet I am working on.

Basically, I have a function of x called psi_I and I want to define another function of x called psi_I,d which is just the derivative of psi_I.

In, the snippet below, this works if I use the variable names psi_1 and psi_1,d, but not if I replace the "1" with a "I" as I want to do.

In addition, I don't know why the output (6) is different from (7) or (8). All three are from the same command in Maple.

Download psi_subscript.mw

i want to to get the eq(14) but i need to do some Hard replacing which i am unfamiliar with it any one can help ?

Download get_result.mw

I would like to generate a brief description of the object Iterator:-Product but I get the following error:  

Describe(Iterator:-Product);

object Product :: Class<<36893490916968945900>>:

    ModuleApply( )

    ModuleCopy( self::_Product, proto::_Product, 
Error, (in Describe) `proto` does not evaluate to a module

How do I get rid of this message? 

i used: 
Y := ssystem("dir C:"); print(Y)
result is

[0,"\" El volumen de la unidad C es OS\n El n£mero de serie del volumen es: 54A9-09DA\n\n Directorio de C:\\Program Files\\Maple 2016"

Windows operating system English version but Maple shows Spanish result
I want result is English. Please help me

Download language_maple.mw

Hello,

non-expert Maple user here.  Any help would be appreciated, I am trying to perform the following process:

1) Represent State Space matrices calculated by hand (ex: A, B, C, D) as a Maple object.

2) Find a solution to the State Space system of equations based on given initial conditions, or represent the same in any other form such as a plot or table.  I am right now trying without much success to use the ResponsePlot and Simulate functions for this.

I have completed (1) using the DynamicSystems > StateSpace object of the form

sys:= StateSpace(A,B,C,D)    // where A, B, C, D are the numeric matrices of the typical S-S set.

using a simple constant '1' as an algebraic input test, I use the ResponsePlot as follows:

ResponsePlot(sys, 1) 

Maple gives me the error: 

Error, (in DynamicSystems:-Simulate) for a continuous system, the second argument (input) must be an algebraic expression or a list of algebraic expressions; received Vector(7, [0,1,2,3,4,5,6])
NULL;

I am sure I'm missing something simple.  Can someone please assist in showing me what I'm doing wrong?  I tried using a vector [0,1,2,3,4] instead of an algebraic function, but it still returned an error.  I am open to other ways too, but the next best way seems to be to convert from StateSpace into individual differential equations and then solve them all manually with dsolve.  It seems like there has got to be a simpler way than that.  Does anyone know of a simple way to implement this process?

i did try but i don't know the result is not come out? also i am not sure to put equation in eq1 in pde or linear part?

Download parameters.mw

Can I define the creation and annihilation operator commutation relations with an explicit momentum dependence?

The goal is to implement an expression of a discrete scalar plane-wave solution to the Klein-Gordon equation that makes use of the creation and annihilation operators in the Physics package.

We don't bother solving the Klein-Gordon equation explicitly. Instead, we just take a solution from literature. This approach is sufficient to show the difficulty in defining the the creation and annihilation operators in this way.

how_to_define_creation_and_annihilation_operators_with_a_momentum_dependence.mw

Download how_to_define_creation_and_annihilation_operators_with_a_momentum_dependence.mw

Whenever I have local proc inside a proc, and use local variables from the outer proc inside it, Mint tells me that the variables are not used.

This can't be right. Why does it say that? Here is MWE. I have this foo.mpl file

foo := proc()

local C1;
local y,x;

    proc()
        C1:= `tools/genglobal`(_C); 
        sol:=y(x)=  C1; 
    end proc();

end proc;

We see clearly that C1 is used, also x and y are used. There can be more code using these inside the inner proc. But this is what mint says

"C:\Program Files\Maple 2024\bin.X86_64_WINDOWS\mint.exe" foo.mpl

    |\^/|      Maple 2024 Diagnostic Program
._|\|   |/|_.  Copyright (c) Maplesoft, a division of Waterloo Maple Inc. 2024
 \  MINT   /   All rights reserved. Maple is a trademark of
 <____ ____>   Waterloo Maple Inc.
      |
Procedure foo() on lines 1 to 11
  These local variables were never used:  C1, x, y

Any idea why it says these are not used?

Also, I noticed it did not warn me that variable sol is global inside the proc. i.e. I was expecting something like this 

          These names were used as global names but were not declared: sol

Which is typical message mint gives when using a name inside a proc which was not declared,

Maple 2024.2 on Windows

I have a square matrix of data points. Each point is between 0 to 0.2. I wish to plot it and set the axes to values from 0 to 1. I want the 3D plot to be plotted with a constrained scaling. The two options I have are plots:-matrixplot and plots:-surfdata. 

* matrixplot can constrain the data, but it isn't obvious how to change the axes so that it shows from 0 to 1 in both directions. 

* In surfaceplot, it is easy to adjust the axes values, but scaling=constrained does nothing. 

(I assume someone else might also appreciate the answer. So, instead of me continuing to struggle, I post here and hope someone can answer without the use of many brain cells.) 

Example attached.

Download Scaled_matrix_plot_with_axes.mw

If I understand right, in the following calling an exception should be raised since the return value of the matching coercion procedure is of course not of type “set”: 

restart;
foo := (x::coerce(set, (y::rtable) -> convert(y, list))) -> x:
foo(<0>);
 = 
                              [0]

Did I miss something?

So just like the title illustrates, I found a paper authored by Gary Nicklason in 2022: Autonomous Planar Systems of Riccati Type and in the last section it mentioned about a class of Abel ODE, which belongs to AIA(Abel Inverse Abel) class. It is of First kind and the inverse of it(by swapping variables) is of second kind.

While the first kind is solvable in terms of Airy function, the inverse of it along with its equivalence class is not solvable by the existing dsolve.

I have tested it in my worksheet Nicklason_equation.mw. So is it possible to add this class into the dictionary for solvable Abel ODE, or, maybe there are some bugs within the internal procedure of dsolve, which results in failure for catching the solvable candidates?

I want to remove the Lambert function (LambertW) from my equation, but I don't know how. I tried using the explicit option, but it didn't work. How can I express the equation without LambertW?

Download remove.mw

I have a system of polynomial equations where the unknowns are real numbers. The set of solutions is infinite (positive-dimensional). How can I compute the real dimension of the solution set (i.e. of a real algebraic variety)?

As it as mentioned in arXiv:2105.10255, this can be done using the RealTriangularize function from the RegularChains package. What is best way of getting the real dimension from the regular_semi_algebraic_system object, which is returned by this function?

I got email to register to "see" Maple 2025 :

for a special advanced look at Maple 2025

But I do not understand what does registering here means. Do I then get a link to some Maple internal URL to watch Video at that time? It says

Date/Time: Tuesday, March 18, 2025 at 11:00 AM
Language: English
Duration: 1 hour

If I register, then what happens?  do I get a link that opens at the time time to watch it? If so, why does one have to register to watch a Maple video? Why is the link not made public for any one to watch? Does one have to be at the browser at that exact time for the link to open?

I just do not know what a Maple webinar means.  Is it like a youtube video?