Unanswered Questions

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

There seems to be a regression in Maple 2026 in the XMLTools:-ParseFile function.

As Maple2026 is not yet in the list of products to be chosen, I have added it in the subject.

Error, (in XMLTools:-ParseFile) invalid input: too many and/or wrong type of arguments passed to XMLTools:-NSXML:-Parser:-ParseFile; first unused argument is prolog = true

The test file is right from the help related to ParseFile.
Test_XML.mw

I'm new to MapleFlow, and I have a few questions about MapleFlow help.

  1. I read the recent post about the release of MapleFlow 2025.2, and it mentions some new functionality and bug fixes.  Is there a "What's new in MaplleFlow 2025.2" section in a help file, online or offline, that lists the new features and bug fixes?
  2. I can find Online Help for Maple, MapleSim and MapleSim Toolboxes, but I can't find a section for MapleFlow.  I realize that MapleFlow and Maple share a lot of functionality, so the Maple section covers the functions, but there are MapleFlow-specific features that don't seem to have their own section in the Online help.
  3. The offline MapleFlow help seems rather dated and limited.  When was the last time any updates were made?  Are there plans to continue to improve the offline MapleFlow help?
  4. I have a few tech support questions in, and I have received some feedback, but at least one has been sent to the Math group for review, and it's been about a week, and I've heard nothing.  Is there somewhere we can check the status of our tech support issues?

Thanks

Objective: Solve a system of two equations.

Obstacle: Generating these two equations depends on millions of previous combinations as well as derivatives.

In other words, we've reached the maximum limit that Maple on my computer can handle.

What would be better, to leave the equations aside or to upgrade my computer?

restart

with(plots)

with(linalg)

H01 := -gamma11*S11-gamma12*S12-gamma13*S13-gamma14*S14-gamma15*S15-gamma16*S16-gamma17*S17-gamma18*S18-gamma19*S19-gamma110*S110-gamma111*S111-gamma112*S112-eta1*(S11^2+S110^2+S111^2+S112^2+S12^2+S13^2+S14^2+S15^2+S16^2+S17^2+S18^2+S19^2)-J1*(S11*S12+S12*S13+S13*S14+S14*S18+S18*S112+S112*S111+S111*S110+S110*S19+S19*S15+S15*S11+S16*(S12+S110+S15+S17)+S17*(S113+S111+S18))

H02 := -gamma21*S21-gamma22*S22-gamma23*S23-gamma24*S24-gamma25*S25-gamma26*S26-gamma27*S27-gamma28*S28-gamma29*S29-gamma210*S210-gamma211*S211-gamma212*S212-eta2*(S21^2+S210^2+S211^2+S212^2+S22^2+S23^2+S24^2+S25^2+S26^2+S27^2+S28^2+S29^2)-J1*(S21*S22+S22*S23+S23*S24+S24*S28+S28*S212+S212*S211+S211*S210+S210*S29+S29*S25+S25*S21+S26*(S22+S210+S25+S27)+S27*(S213+S211+S28))

Z01 := exp(-beta*H01)

Z01 := add(add(add(add(add(add(add(add(add(add(add(add(Z01, S11 = [-2, -1, 0, 1, 2]), S12 = [-2, -1, 0, 1, 2]), S13 = [-2, -1, 0, 1, 2]), S14 = [-2, -1, 0, 1, 2]), S15 = [-2, -1, 0, 1, 2]), S16 = [-2, -1, 0, 1, 2]), S17 = [-2, -1, 0, 1, 2]), S18 = [-2, -1, 0, 1, 2]), S19 = [-2, -1, 0, 1, 2]), S110 = [-2, -1, 0, 1, 2]), S111 = [-2, -1, 0, 1, 2]), S112 = [-2, -1, 0, 1, 2])

NULL

Z02 := exp(-beta*H02)

Z02 := add(add(add(add(add(add(add(add(add(add(add(add(Z02, S21 = [-2, -1, 0, 1, 2]), S22 = [-2, -1, 0, 1, 2]), S23 = [-2, -1, 0, 1, 2]), S24 = [-2, -1, 0, 1, 2]), S25 = [-2, -1, 0, 1, 2]), S26 = [-2, -1, 0, 1, 2]), S27 = [-2, -1, 0, 1, 2]), S28 = [-2, -1, 0, 1, 2]), S29 = [-2, -1, 0, 1, 2]), S210 = [-2, -1, 0, 1, 2]), S211 = [-2, -1, 0, 1, 2]), S212 = [-2, -1, 0, 1, 2])

NULL

G0 := -(1/24)*N*ln(Z01*Z02)/beta

NULL

m01 := -24*(diff(G0, gamma11))/N

m02 := -24*(diff(G0, gamma21))/N

NULL

beta := 11.605/T; gamma11 := 2*J1*m1+2*J2*m2; eta1 := Delta; gamma21 := 2*J1*m2+2*J2*m1; eta2 := Delta; gamma12 := J1*m1+2*J2*m2; gamma22 := J1*m2+2*J2*m1; gamma13 := J1*m1+2*J2*m2; gamma23 := J1*m2+2*J2*m1; gamma14 := 2*J1*m1+2*J2*m2; gamma24 := 2*J1*m2+2*J2*m1; gamma15 := J1*m1+2*J2*m2; gamma25 := J1*m2+2*J2*m1; gamma16 := 2*J2*m2; gamma26 := 2*J2*m1; gamma17 := 2*J2*m2; gamma27 := 2*J2*m1; gamma18 := J1*m1+2*J2*m2; gamma28 := J1*m2+2*J2*m1; gamma19 := 2*J1*m1+2*J2*m2; gamma29 := 2*J1*m2+2*J2*m1; gamma110 := J1*m1+2*J2*m2; gamma210 := J1*m2+2*J2*m1; gamma111 := J1*m1+2*J2*m2; gamma211 := J1*m2+2*J2*m1; gamma112 := 2*J1*m1+2*J2*m2; gamma212 := 2*J1*m2+2*J2*m1

NULL

eq1 := m1 = m01

eq2 := m2 = m02

fsolve(subs(J1 = 2*.83, N = 1, J2 = -2*.58, Delta = 0, m1 = 0.1e-1, {eq1, eq2}), {T, m2}, T = 0 .. 220, m2 = -.1 .. .1)

fsolve(subs(J1 = 2*.83, N = 1, J2 = -2*.58, T = 1, Delta = 0, {eq1, eq2}), {m1, m2}, m1 = -5 .. 5, m2 = -5 .. 5)

{m1 = 2.000000000, m2 = -2.000000000}

(1)

NULL

Download Maple_forum_test.mw

After system restart on Windows 11:

Maple 2026 was installed as usual with administrator rights and with import of preferences from Maple 2025. Other Maple versions are working on the same computer.

Does this never-seen-before output gives a hint what is wrong with my installation. Any suggestions what to do next?

That's the installed version:

On the same Windows 11 installation, Maple 2025 displays equation labels but Maple 2026 not. Maple 2025 settings were imported for the 2026 installation. (Crtl-l + number does return "invalid label". I assume that not labels have been generated)

Has anbody observed the same? Any suggestions what I could check/do?

Other observation: The output font does not look the same

 

Is there an easy way to read jld files in Maple?  Apparently JLD (Julia Data) and JLD2 files are binary formats primarily designed for saving and loading Julia variables, preserving types.

That's how it looks like in Maple 2026.0 for the Examples on the Help-page for topic solve, on Windows 11

For a fraction of a second I see output rendered in blue and Math-2D. Then it turns to the above.

Is this a regression or a new feature? How to get the output back to Math-2D and blue?

Glad that 2026 has been released now, and I will certainly use it as the default version in the future.

While there are a lot of new features, one thing that keeps annoying me is the inferior font quality, compared to other software.

Here's a screenshot of 4 different programs, all with font Arial 11pt and 100% zoom factor. Font AntiAliasing is set to enabled in Maple.

Judge it for yourself, but in my opinion it gives a clear picture that Maple is much worse to read than any of the other software packages (Word, LibreOffice, pdfXChange).

In the Maple 2025 release, the "old/former" user interface was provided under a menu entry called "Maple 2025 for Screen Readers". I used this version because of shortcommings of the new ribbon interface. Some of the shortcommings have been fixed in the 2026 release but it is still slow to use (I am missing functions in the quick access toolbar that I frequently use and no customization of the bar seems possible).

I could not find a similar menu entry in the 2026 release under Windows 11. Is the old unser interface still available?

I am solving a hybrid nanofluid flow problem in a bifurcated artery using Maple. The governing equations for velocity and temperature are solved using dsolve(..., numeric, method=bvp[midrich]).

My Maple code successfully produces for both the artery  parentartery_and_daughter_artery_error.mw.

The velocity profiles are obtained correctly using odeplot.

However, I want to compute additional physical quantities and generate plots similar to the velocity profiles.

Specifically I want to plot:

  1. Flow rate Q versus axial distance z

  2. Impedance (flow resistance) λ versus z

  3. Wall shear stress τ versus z

for different values of Hartmann number Ha.

The formulas I am using are

Flow rate:

Q=2π(R∫01ηw(η) dη+R2∫01w(η) dη)Q = 2\pi \left( R \int_0^1 \eta w(\eta)\,d\eta + R_2 \int_0^1 w(\eta)\,d\eta \right)Q=2π(R∫01​ηw(η)dη+R2​∫01​w(η)dη)

Wall shear stress:

τ=μ∣dwdr∣\tau = \mu \left|\frac{dw}{dr}\right|τ=μ​drdw​​

Impedance:

λ=∣dp/dz∣Q\lambda = \frac{|dp/dz|}{Q}λ=Q∣dp/dz∣​
Please help me to solve this question.

I have attached a MapleFlow file that shows a result I don't quite understand.  For some reason the FinalValue result that I get using the DynamicSystems:-StepProperties is different than the steady state value from a DynamicSystems:-ResponsePlot to a unit step using a DifferentialEquation object.

You will notice that I played around a bit, including transforming the DiffEquation object to a TransferFunction object, to see if I could make sense of it.  All of the results are the same as the StepProperties result, it appears that only the ResponsePlot for the DifferentialEquation object is different.

Am I doing something wrong?  Does anyone have any ideas?

Dynamic_Systems_Final_Value.flow

I am not sure whether this should be in "create a post" or "ask a question." Let me know if this is more appropriate in "ask a question"

The standing wave equation is given by:

PDE:=diff(u(x,t),t,t)=c^2*diff(u(x,t),x,x)

IBC := {u(x, 0) = A0*cos(Pi*x/L), D[1](u)(0, t) = 0, D[1](u)(L, t) = 0, D[2](u)(x, 0) = 0}

pdsolve(PDE,IBC,numeric)

In my problem, the material is a magneto-elastic material where c, the speed of the acoustic wave, is a function of a magnetic field H.  The material is nonlinear and saturable.  I define it by a 3 segment piecewise nonlinear function of H.  The material response is a result of a sinusoidal H field.  I am interested in solving u(x,t).  

With that, c in the PDE has to be rewritten as c(H(t)), pdsolve gives an error as PDE has to be expressed as a function of u,t, or x.  So I redefine c(H(t)) as c(t).  I ran into another error in pdsolve as the piecewise has to be based on t or x and not H.  

The problem is that depending on H I can go through all 3 segments and back in one cycle and I have to find the corresponding t's for the piecewise.  Now I am driving the material with 100 cycles, I have to find and list all those piecewise transition points which is hardly practical.

Is there any other ways to approach and solve this problem?

once i founded but  i lost the technique and i can't remember how i can reach the point how to find thus parameter and find the solution of pde

t1.mw

I just found a rather incredible error in versions 2025.1 and 2025.2.

The function works fine in version 2022.

The drag function in solve does not work, even for solving a very simple problem.

For example, in the equation 1 + 5x = 3x - 1, if I try to do 3x from right to left, a box opens with a good suggestion (subtract   1+2x = -1)

# subtract 3*x from both sides
((1)) + ~(3 * x)
we can see that the correct expression should be ((1)) - ~(3 * x)

I finally get:

1 + 8x = 6x -1 (it added and did not subtract 3x from both sides)

Please correct this...

Mapleprimes issue

Trying to upload a mw file throws this error message

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