It's becoming increasingly common for questions to be deleted, the most frequently evoked argument being that they duplicate earlier questions.
Usually it's the author of the question who complains, in this case it's the one who provided an answer.

I've always found this self-given freedom on the part of moderators somewhat inappropriate, especially given that these deletions are done on the sly, without even the courage to be explicitly claimed by their authors.

Couldn't these latter take the time to leave a message indicating what they've just done (and why) and where the deleted question, and any exchanges associated with it, can be found?
Otherwise, this attitude is more akin to contempt and censorship than to real management of this blog.

A few years ago, when I came to this site, these deletions were the exception and I can only deplore the fact that they have become commonplace.
They say that life is better elsewhere, I don't know, but what I do know is that I've never come across this on any Scilab, R, SageMath or OpenTurns user's blog.

Anyway, here's the reply I sent to @salim-barzani :  Hirota_derivative_KdV_equation.mw

Is it possible to configure newer maple versions to use a different file extension ?

I have a lot of  Maple 9 files  with .mw extension. I dont want them opened and saved by a later version as they are valuable and actually work better than later maple versions which throws unneccesary signum errors. The results are verified so the signum errors are bogus in the recent maple versions running the same file.

Particularly, can I configure e.g. Maple 2022 to save to a different file extension say .mww or similar rather than .mw so I can avoid destroying to original 9.5 files?

Hi everyone!  I'm trying to study a certain function.  The output says that, from -5 to 5, the output is undefined.  Am I doing something wrong?

Thanks in advance.

range_not_undefined.mw

Dear friends,

I need a procedure to classify a list of polynomials by their leading monomials. For example, if F = [x^2 - y - 1, y^2 - y, x^2 - 4, y^3 - 1, z^2 - 4] and a < be the lex ordering s.t. z<y<x, it should return [[x^2 - y - 1, x^2 - 4], [y^3 - y, y^3 - 1], [z^2 - 4]]. 

I appreciate any help you can provide.

Sincerely,

A gardener wants to spread 25 roses over an area so that there are 5 roses in each of 15 straight rows. The roses should be arranged rotationally symmetrically so that more than 3/4 of them are less than half as far from the center of symmetry as the outermost ones and that the center of symmetry itself remains unplanted. How is such an arrangement possible?

What is the correct syntax to do this change of variable from the text book:

The problem is that using PDEtools:-dchange, it wants the transformation to have form { old = new}, i.e. x=...  so I can not write  z=g(x) in the transformation. 

For example

ode:= diff(y(x),x$2)+diff(y(x),x)+y(x)=sin(x);
PDEtools:-dchange({z= g(x)},ode,known={x},unknown={z});

Error, (in dchange/info) missing a list with the new variables
And if I first solve for x so that I can write the transformation with x on left side, it still does not work

ode:= diff(y(x),x$2)+diff(y(x),x)+y(x)=sin(x);
PDEtools:-dchange({x=RootOf(g(_Z) - z)},ode,known={x},unknown={z});

Where RootOf(g(_Z) - z) was result of solve(z=g(x),x);

I am sure this can be done in Maple, I just do not know the right syntax to use with dchange.

Maple 2024.2

What systematic methods can be used to determine the optimal parameters in a long equation involving two independent variables, and how do techniques like separation of variables, balancing principles, or dimensional analysis aid in simplifying and solving such equations?

parameters_x_t.mw

Imagine that the following summation needs to be constructed to create a graph. Suppose the text below provides us with this relationship between the equations

The table below further provides us with such relationships.

If we assume that the unprovided constants are equal to 1, then what does a graph look like for the remaining variables?

I have difficulty implementing a system containing sums

I am trying to model the change in bloodglucose when performing a OGTT (Oral glucose tolerance test). In connection to this I've created a compartmentmodel consisting of two compartments; one for the stomach and one for the blood. Based on this compartmentmodel I've formulated two differentialequations describing how the glucose concentration in respectively the stomach and the blood changes. I've then solved this system of differential equations and I'm now trying to adjust the variables to make the graphs look like the one from a glucose tolerance test but I'm having trouble creating an Explore-plot.

Download Explore_plot.mw

Hi!

So I like to check that my manual integrations and/or maple integrations are equal with each other. I normally do this using the Test Relation function.

I was working on a problem and noticed that Maple didn't evaluate the integrals being the same, even though they presumedly are.

Could anyone shed some light on why I get this inequality?

Thanks in advance!

mapleintvsmanualint.mw

Download mapleintvsmanualint.mw

The uploaded worksheet defines a surface.

I would like to code a ball rolling across this surface (and others) starting from an initial position on the surface and an initial velocity tangent to the surface, but I don't know how to do this.

What is the combination of physics (including gravity) and math that accomplishes this task?

Ball-rolling-on-a-surface.mw

Is there a trick to make Maple give same result below when using eval and limit?  

Attached worksheet. This comes in context of solving ode  using Laplace. Initial conditions are at zero. And need to solve for the constant of integration. 

It works when using eval, since Dirac(t) becomes Dirac(0), but when using Limit, Dirac(t) becomes zero and the _C1 is lost. I was wondering if limit should also return Dirac(0) like eval?

Download dirac_limit_dec_13_2024.mw

Some of the calculations mentioned here can be done in alternative programming languages, such as Python, C, and so on. However, I would like to reproduce exactly these graphs using Maple (without the need for programming commands, such as "if", "while", among others).

In the work I am trying to reproduce, we have "The evaluation of the influence of the inclusion of the broadband behavior of grounding systems in EMT-type programs in the evaluation of transients resulting from direct lightning strikes on transmission lines. The behavior of the grounding frequency is determined using an accurate electromagnetic model and included in the EMTP/ATP by means of an equivalent circuit derived from the Vector Fitting technique. In addition, the impact of the frequency dependence of soil parameters on the lightning performance of transmission lines is addressed." This may seem somewhat disconnected from reality for many, since it is a problem involving electrical engineering optimization.

Could someone help me reproduce these calculations? I have made little significant progress.

If you want to access the reference accounts, I'll send you the PDF

schroeder2017 [link to copyrighted material replaced by moderator]

Hello Dear Maple Users and Experts

I am running this code for N=3, but fsoolve can not work and did not give me any output. Could you help me how can I get the result?

Actually, I got the result for N=2. Exact solution is a[0]=0, a[1]=1, a[2]=1, b[1]^2=sqrt(2) and b[1]^2+b[2]^2=sqrt(3). But, for N=3, I can not receive any results from fsolve

Here is my code

restart;
Digits := 20;
L := 1;
N := 3;
alpha := 1;
xexact := t -> t^sqrt(2) + t^sqrt(3);
f := simplify(fracdiff(t^sqrt(2), t, alpha)) + simplify(fracdiff(t^sqrt(3), t, alpha));
f := unapply(f, t);
xapp := a[0] + sum(a[j]*t^sum(b[i]^2, i = 1 .. j), j = 1 .. N);
xapp := unapply(xapp, t);
xfrac := sum(a[jj]*simplify(GAMMA(sum(b[ii]^2, ii = 1 .. jj) + 1)/GAMMA(sum(b[ii]^2, ii = 1 .. jj) + 1 - alpha))*t^(sum(b[ii]^2, ii = 1 .. jj) - alpha), jj = 1 .. N);
xfrac := unapply(xfrac, t);
xfrac1 := sum(a[jj]*simplify(sum(b[ii]^2, ii = 1 .. jj)^(alpha + 1)/(sum(b[ii]^2, ii = 1 .. jj) - alpha))*t^(sum(b[ii]^2, ii = 1 .. jj) - alpha), jj = 1 .. N);
xfrac1 := unapply(xfrac1, t);
S1 := {seq(evalf(xfrac(k/(2*N)*L)) - evalf(f(k/(2*N)*L)) = 0, k = 1 .. 2*N)};
S2 := {xapp(0) = 0};
S := S1 union S2;
sol := fsolve(S);