"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

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

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: 

Is it possible to install and operate Maple toolbox 2025.2 with MATLAB R2025b on Linux (Ubuntu 24.04)  platform?

On Ubuntu 24.04 installation process hangs after location of Maple and Matlab folders at installer window.

Any idea what is wrong?

Of course, I know that actual Maple 2025 system requirements mention support only for MATLAB R2024b, but this is an obsolete version of MATLAB.

And finally, Is there any reliable and effective way how to switch between Maple and MATLAB symbolic engine?

When I use Maple to solve some complex polynomial system and trying different methods, for instance, using engine = traditional, it will sometimes lose or fail to find the solutions. In the document, it says Maple will convert to engine = groebner when it does not find solutions using traditional engine. As far as I know it is using resultant to eliminate variables, and the resultant is computed by pseudo remainder. The leading coefficient of the divisor is multiplied during each division to ensure that we include the case that it is zero.

But why this procedure will lose solutions sometimes? What makes Maple abandon this method?

Hello, sirs, I need your help to plot a contour for Psi; for this, y should be on the vertical axis and x on the horizontal axis.  My Maple sheet is working, but the output is not according to the desired. Can you please have a look, and for reference, I am uploading a picture. I need my contour to look like the reference picture.

Contour_plot_help.mw

It hangs are v(x) := for some reason.

NULL;

q := x -> v1*Dirac(x - a1) + v2*Dirac(x - a2) + v3*Dirac(x - a3);
NULL;

V := x -> -int(q(x), x = 0 .. x) + Ra + Rb*Dirac(x - L);
proc (x) options operator, arrow, function_assign; Units:-Simple\

  :-`+`(Units:-Simple:-`+`(Units:-Simple:-`-`(MTM:-int(q(x), x 

   = 0 .. x)), Ra), Units:-Simple:-`*`(Rb, Dirac(Units:-Simple:-\

  `+`(x, `-`(L))))) end proc

NULL;

M := x -> int(V(x), x = 0 .. x) + Ma + Mb*Dirac(x - L);
proc (x) options operator, arrow, function_assign; Units:-Simple\

  :-`+`(Units:-Simple:-`+`(MTM:-int(V(x), x = 0 .. x), Ma), 

   Units:-Simple:-`*`(Mb, Dirac(Units:-Simple:-`+`(x, 

   `-`(L))))) end proc

theta := x -> 1000000000000*(int(M(x), x = 0 .. x) + `θa` + `θb`*Dirac(x - L))/(E*S_mm);
proc (x) options operator, arrow, function_assign; Units:-Simple\

  :-`*`(Units:-Simple:-`+`(Units:-Simple:-`+`(MTM:-int(M(x), x 

   = 0 .. x), `θa`), Units:-Simple:-`*`(`θb`, 

   Dirac(Units:-Simple:-`+`(x, `-`(L))))), 1/(E*S_mm*10^(-12))) 

   end proc

v := x -> int(theta(x), x = 0 .. x);
proc (x) options operator, arrow, function_assign; MTM:-int(thet\

  a(x), x = 0 .. x) end proc

I get this message:

Why is it not working using the menu?

Why are characters printed with additional back ticks when decimal HTML code is used (see output (3) below). lprint((3)) does not print them.

Looks like an exception. Is there a reason for that? Can it be used for something?

Download back_ticks_with_decimal_code.mw

Good afternoon.

Here is (what appears to be) a simple assignment problem that involves scheduling 3 jobs through 2 machines, and I wish to minimize the total time required to complete all 3 jobs. Each job must be processed first on machine #1 before going to machine #2,and each machine can only handle one job at a time.

I have determined the optimal sequence to minimize the makespan (i.e., the completion time of the last job on machine #2) using a manual method and I was wondering if someone could review this (please see attached) and recommend a structured LP method or let me know if such a procedure exists in Maple's Optimization package.

Any help will be appreciated! 

Thanks for reading.

MaplePrimes_Nov_4.mw

I want to write the equation of the line in the form a*x + b*y + c=0, with igcd(a,b,c)=1 of this code

restart;
with(geometry);
point(A, 2, -3);
point(B, -1, 6);
sort(Equation(line(d, [A, B], [x, y])));

I tried by hand

-1/3*sort(Equation(line(d, [A, B], [x, y])))

How can I get the result 3x + y - 3=0 automatically?

PS. I tried and get the answer 3x + y - 3 =0.

restart;
with(geometry);
point(A, 2, -3);
point(B, -1, 6);
eq := sort(Equation(line(AB, [A, B], [x, y])));
k := igcd(coeff(lhs(eq), x), coeff(lhs(eq), y));
sort(eq*sign(coeff(lhs(eq), x))/k);

Embedded typesetting code in names is still giving me troubles. This is because the functionality and interplay of the characters ", &, #, ; and ` are not documented (appart from some MaplePrimes posts). Sometimes an escape  character (is that term correct?) is required sometimes it can be omitted or replaced by something else. I read somewhere that in former Maple versions strings were composed with back ticks `...` and this has moved to double quotes but both ways work for typesetting (if one knows how to).

Overall, there is allot of guesswork and trial-and-error involved in typesetting.

In the below I discovered a pecularity that prevented me to add certain symbols to the favorite palette.

On the positive side I found anwsers for an older question. On negative side an atomic identity has to be converted to atomic to add it to the favourites. This confuses me.

Maybe someone knows why this has to be done? Does a dragg operation strips of certain characters? Or is it in the case below that the use of the ampersand plays a role which is normally reserved to define neutral operators. Or is it fully unrelated because HTML codes and HTML entities for special symbols start with an ampersand (however an &D entitiy does not seem to exist).

Besides an explanation for the double atomization any insights and guidance with repect to typesetting of names is highly appreciated. Creating an italic captial D as a variable/name has been anwsered to my full satisfaction here. This question is more about a better understanding of typesetting.

Download dragging_atomic.mw

After Maple 2025 start-up (with disabled start-up page) and closing the blank worksheet (note the dark grey workspace) there is still one mserver running (highlighted in yellow).

I have not seen a difference when I kill this process and open a new worksheet which starts a new mserver.exe task (and run Maple code).

The task seems to be inactive (no processor load and memory allocation visible).

Is it a task only used by the interface task (javaw.exe)?
What might be the purpose of this mserver.exe? 

Update: The task is inactive in a sense that it does not show immetiate activity when annother mserver.exe task runs (i.e. exceuting a worksheet). However, after a day memory allocation shows changes. When exactly these changes happend is unclear.

Although several similar problems were asked many years ago (see, e.g., the section “Formal linear algebra” here), there appears to be no new progress so far. It is said that such functionalities exists in the Physics package, but I cannot find any corresponding examples. 
In short, can Maple at present calculate these examples in terms of symbolic array constructs completely automatically?