In 2025.2, I found that calling Physics:-Setup causes code of `convert/diff` to change (on the fly) causing error.

I removed from my code the places I was calling Physics:-Setup explicitly, but the error still shows up. Which means there is still places in the code to cause Physics to come into play.

I just installed 2025.2 and have not done anything yet. Just running a test. 

Does one need to install Physics package?

First, let me give an example showing that calling Physics:-Setup changes `convert/diff` which ends up causing an internal Maple error

Download why_code_changes_calling_Physics_maple_2025_2_nov_24_2025.mw

Notice that now calling PDEtools:-difforder(convert(T,diff))  fail because Physics:- was called.

But my code now has no calls to Physics:-, I made sure to comment all those out. 

But I still get same error when I run my test program. Not able to find where Physics is "activated" again to cause the code change in `convert/diff` that happens dynamically when Physics is loaded.

It must be happining on different call internally. But have no idea why and where.

This is all on new PC. I have no Maple ini files or anything like this that can cause this.

Will installing Physics package explicity fixes this?   

Update

I think I know why this happens. Not all fixes made by Edgardo S. Cheb-Terrab in last Physics update are included in Maple 2025.2 !

See https://mapleprimes.com/questions/240843-Why-PDEtoolsSolve-Fail-On-This-Equation  where fix is made in Physics  v.1880 which I confirmed in Maple 2025.1.

But now I checked and this problem is back in Maple 2025.2. which means that fix was not merged into Maple 2025.2. How could this happen?

Download fixed_in_2025_1_but_missing_in_2025_2.mw

So I am hoping that figuring how to install Physics update in Maple 2025.2 will fix the current problem with convert and also bring that old fix for PDEtools:-Solve back into Maple 2025.2.

This is something that Maplesoft should have taken care of.

Update 

Figured how install Physics update package V 1881 and doing so fixed this problem in Maple 2025.2 !

This tells me that all fixes that were in Physics update package were not merged into Maple 2025.2

This worksheet shows that now code works OK, but need to make sure to install Physics update package in Maple 2025.2

Download why_code_changes_calling_Physics_maple_2025_2_nov_24_2025_V2.mw

I cannot get the ini file to load packages.  It executes fine and the bottom commands work, but the package does not load.
Is there some special way to load packages in the ini file?

Thanks!

with(LinearAlgebra):
    stoperror(all):
    interface(displayprecision = 4);
    _EnvUseHeavisideAsUnitStep := true;  
    Digits := 10;
    printf("Standard Packages Loaded\n");

I've modified the geometry:-intersection example from the help file to show an error which I am struggling to understand.

Why does a redefinition of a geometry object throw an error?

Test_intersection.mw

How to get a 2D plot for the following command: 
error_in_2d_plot_cf_and_nu.mw

The new default in Maple 2025 is to hide the Execution Group Boundaries in Worksheet mode.
In order to make them visible one has to use the menu

View > Show/Hide Contents > Execution Group Boundaries F9

or to press the F9 key.

The question: is there a method to have again visible boundaries by default? 

(Hiding the boundaries does not seem to be a good idea because an execution group can have (it is not clear why!) multiple prompts.)

Dear Maple user, please help me to show two legends inside the plot. Here is the codes attached. restart:
h:=z->1-(delta2/2)*(1 + cos(2*(Pi/L1)*(z - d1 - L1))):
K1:=((4/h(z)^4)-(sin(alpha)/F)-h(z)^2+Nb*h(z)^4):
T1:=Int(K1,z=0..1):
L1:=0.2: F:=10:
d1:=0.2:
T2:=evalf(T1):
T3:=unapply(T2,alpha,Nb,delta2):
plot([seq(seq(T3(alpha, Nb, delta2), Nb in [0.1, 0.2,0.3]), alpha in [Pi/6, Pi/4, Pi/3])], delta2 = 0.02.. 0.1,  titlefont = ["ROMAN", 15], labels = ["δ1", "T3"], labeldirections = ["horizontal", "vertical"], labelfont = ["SYMBOL", 11], linestyle = [solid, solid,solid,longdash, longdash,longdash, spacedash,spacedash, spacedash], symbol = [BOX, CROSS, CIRCLE, BOX, CROSS, CIRCLE, BOX, CROSS, CIRCLE], color = [blue,red, green, blue,red, green,blue,red, green], axes = boxed,size = [1000, 1000]);

I have a problem where there is a true deadtime due to a transport delay.  The delay is in the order of 8 minutes as a fluid flows very slowly down a tube.

I've fit an expression to some measured data and have found the following expression

I'd like to work with this using the Dynamic Systems Package, so I'm trying to build a system from the time-domain expression.  When I try to use the inttrans:-laplace function to convert to the s-domain, I get an overflow.  If I manually express this as a Laplace transform and try to make a system and do a step response, I get this, with an error that "transfer function(s) are not rational-polynomial(s) in s"

Is a delay supported in the Dynamic Systems Package?  If so, could you provide guidance on how?

"Error, (in dsolve/numeric/SC/firststep) unable to evaluate the partial derivatives of f(x,y) for stiff solution", I am trying to solve a system of PDEs in Maple, using discretisation schemes, but keep getting this error. Can anyone help me with this?

i did try and even replace the function w(t) by anotehr thing but is not working  how i can find that and make be answer of my pde?

k1.mw

How can find thus parameters 

Dr.D-problem.mw

In space, how can we find the coordinates of the three vertices of a triangle that is neither right-angled nor isosceles, such that the coordinates of its vertices, the coordinates of the foot of an angle bisector, the length of that angle bisector are all integers, and the lengths of the sides of the triangle are integers? 

I tried 

https://drive.google.com/file/d/1xOMxTCv3lC9RiKpwazerQ3D6WxeXLwJ-/view?usp=sharing

a million time i try to figure out how i can get this plot ? why my graph  in countor is not same the 3D plot? where is problem?

Bgraph1.mw

I am getting an error when trying to pull my value for M_a out of the solver.  See screenshot below.  Full sheet attached.H.Beam_Calcs_Rev00C.flow

I know my sheet is messy so hopefully someone can still understand enough to help me.  The sheet isnt extremely wrong so I'm not sure why I am getting this. I am still new to Maple Flow and learning the tricks of the syntax has been a bit of a struggle

Ladies and Gentlemen,

first question :

what is the equivalent command in Maple to display Mathematica :

$MaxMachineNumber/$MinMachineNumber and $MaxNumber/$MinNumber ?

second question :

How do you "call" the result of a command using ((5)) for example.

I don't know if my English is so bad as to understand the question

A solution would be a great relief for me.

Thank you very much and kind regards,

Jean-Michel

Syntax for merging and overlaying all three graphs on a single plot.
Include three sets of iso-profit lines on the same axes:
– Case 1: thin solid lines
– case 2: brown dashed lines
– Case 3: grey semi-dashed lines
Also add vector arrows to show the direction of maximum profit increase.
Combined plot = Plot 1 + Plot 2 +  Plot 3
Attaching sheet:
case_1.mw                  case_2.mw                 Case_3.mw
 

sample graph: