MaplePrimes - Maple Posts and Questions

Can pdsolve provide solutions for an axially heated rod

C_R — Thu, 16 Jul 2026 13:28:38 Z

I am pretty new to pdsolve.

?pdsolve/numeric states

PDEsys - single or set or list of time-dependent partial differential equations in two independent variables

This could be interpreted in a way that problems with 3 independent variables can be handled (time + two others).

The rest of the helppage only describes two independent variables and does not mention time.

In case the above interpretation is wrong, I have two questions:

If only two independent variables can be treated, why is time-depencency mentioned at all?
Is it possible to integrate the PDE of an axially heated rod of finite length and radius with the help of pdsolve where on one end of the rod a heat flux q=q(r) is applied?

Any links to similar problems solved with Maple (not necessary with pdsolve) are very much appreciated.

Edit: Updated BCs

Download 2d_BVP.mw

How can I define a Tensor equation ?

Mapleliquid — Wed, 15 Jul 2026 16:13:47 Z

Hello,

I want to define these two equations.I know how I can define a Tensor, but how can I use a Tensor with tue diffrent indices. In one case I need u[i] , but I need also u[j]. I know also, that I need an extra command if I want to use latine letters. Can somebody write this complete for me ?

Thank you

Thread-safe alternative to indets?

emendes — Wed, 15 Jul 2026 15:27:12 Z

Hello,

I was wondering whether there is a way to achieve the same result as the code below, but using threads instead of Grid.

The problem is the following. Given a very large list of models (the example below contains only two models), I would like to return a set of sets using a simpler notation for the alpha parameters.

Example

models:=[[y^2*z*alpha[1, 17], z^3*alpha[2, 19], x*z^2*alpha[3, 15] + z^3*alpha[3, 19]], [y^2*z*alpha[1, 17], z^3*alpha[2, 19], x*z^2*alpha[3, 15] + y*z^2*alpha[3, 18]]]:

Desired output

{{[1, 17], [2, 19], [3, 15], [3, 18]}, {[1, 17], [2, 19], [3, 15], [3, 19]}}

The order of the elements does not matter, but the final result should be a set of sets.

The code I am currently using is

svars:={x,y,z}:
Grid:-Set('svars'):
convert(Grid:-Map(w->map(v->[op](v),indets(w,name) minus svars),models),set)

Unfortunately, indets is not listed as thread-safe, so I cannot simply replace Grid:-Map with Threads:-Map.

Is there a thread-safe alternative (or a completely new way of doing the same thing) that would achieve the same result?

Many thanks.

how to collect tanh(xi)

bashar27 — Wed, 15 Jul 2026 14:21:59 Z

equ:=2*(-wu2*w12*JacobiDN(w12*tanh(t*wt1 + wx1*x + b5)^2, m)*JacobiSN(w12*tanh(t*wt1 + wx1*x + b5)^2, m) + wu3*w13 + wu4*w14)*wt1*tanh(t*wt1 + wx1*x + b5)*sech(t*wt1 + wx1*x + b5)^2 + 2*(-wu2*w12*JacobiDN(w12*tanh(t*wt1 + wx1*x + b5)^2, m)*JacobiSN(w12*tanh(t*wt1 + wx1*x + b5)^2, m) + wu3*w13 + wu4*w14)*wx1*tanh(t*wt1 + wx1*x + b5)*sech(t*wt1 + wx1*x + b5)^2 + 2*omega*(b5 + wu2*JacobiCN(w12*tanh(t*wt1 + wx1*x + b5)^2, m) + wu3*w13*tanh(t*wt1 + wx1*x + b5)^2 + wu4*w14*tanh(t*wt1 + wx1*x + b5)^2)*(-wu2*w12*JacobiDN(w12*tanh(t*wt1 + wx1*x + b5)^2, m)*JacobiSN(w12*tanh(t*wt1 + wx1*x + b5)^2, m) + wu3*w13 + wu4*w14)*wx1*tanh(t*wt1 + wx1*x + b5)*sech(t*wt1 + wx1*x + b5)^2 - (48*tanh(t*wt1 + wx1*x + b5)*wx1*sech(t*wt1 + wx1*x + b5)^8*(sinh(t*wt1 + wx1*x + b5)^2*JacobiSN(w12*tanh(t*wt1 + wx1*x + b5)^2, m)^3*JacobiDN(w12*tanh(t*wt1 + wx1*x + b5)^2, m)*m^2*w12^3*wu2 + JacobiCN(w12*tanh(t*wt1 + wx1*x + b5)^2, m)*cosh(t*wt1 + wx1*x + b5)^2*m^2*w12^2*wu2*(cosh(t*wt1 + wx1*x + b5)^2 - 3/2)*JacobiSN(w12*tanh(t*wt1 + wx1*x + b5)^2, m)^2 - (2*JacobiSN(w12*tanh(t*wt1 + wx1*x + b5)^2, m)*(-cosh(t*wt1 + wx1*x + b5)^6/4 + (3*cosh(t*wt1 + wx1*x + b5)^4)/4 + sinh(t*wt1 + wx1*x + b5)^2*w12^2*(m^2 + 1/4))*w12*wu2*JacobiDN(w12*tanh(t*wt1 + wx1*x + b5)^2, m))/3 - cosh(t*wt1 + wx1*x + b5)^2*(3*(cosh(t*wt1 + wx1*x + b5)^2 - 3/2)*w12^2*wu2*JacobiCN(w12*tanh(t*wt1 + wx1*x + b5)^2, m) + cosh(t*wt1 + wx1*x + b5)^2*(cosh(t*wt1 + wx1*x + b5)^2 - 3)*(w13*wu3 + w14*wu4))/6)*wt1^2)*NULL

Recurrence relations in two variables

Geoff — Wed, 15 Jul 2026 06:52:09 Z

Can Maple solve recurrence relations involving two variables?

For example, consider the relation:

P(n, m) = p*P(n - 1, m) + (1 - p)*P(n, m - 1)

with boundary conditions:

P(n, 0) = 0, P(0, m) = 1

I’d like to know how to obtain a solution for P(n, m) in Maple.

Why does Text appear like 12 pt, with a style-set?

erik10 — Tue, 14 Jul 2026 00:49:28 Z

For many years I have used my own Style Set in Maple, mainly by adding a few extra heading styles (typically coloured headings). This has worked very well.

In Maple 2026, the default body text font has been changed to DejaVu Sans. Since the mathematical notation is still displayed in a serif math font (for obvious reasons), I feel that 12 pt DejaVu Sans appears noticeably larger than the mathematics because of its relatively large x-height. To my eyes, 11 pt gives a much more harmonious balance.

I therefore tried to change the built-in Text style from 12 pt to 11 pt.

However, I noticed something very strange.

When I open Style Management, select Text, and click Modify, the Character Style dialog already shows the font size as 11 pt (see the first screenshot). Nevertheless, when I switch to Text mode and start typing, the body text is still created as 12 pt, and the toolbar also reports a font size of 12 pt.

If I create my own custom style (for example, text11) with a font size of 11 pt, it works exactly as expected.

Is the built-in Text style intentionally overridden somewhere by the default Style Set, or is this a bug?

For comparison, I have also attached a second screenshot showing the visual difference between 12 pt and 11 pt body text. In my opinion, the 11 pt version blends much better with the mathematical notation.