There is an integration method called orering in Maple. But see no mention on it at help page 

It shows up when using option 

method=_RETURNVERBOSE

And that is how I knew about it.

It gives division by zero when asked to integrate zero !

Any one knows what is this method? Will send bug email to Maplesoft suport just in case also.
 

Download division_by_zero_int_orering_method.mw

Dear all, how can I simplify the following command by using nested SEQ?

tagsCornersPlot := textplot3d([[seq(cornerPoints[1 .. dim, 1]), cornerPoints[1 .. dim, 1]], [seq(cornerPoints[1 .. dim, 2]), cornerPoints[1 .. dim, 2]], [seq(cornerPoints[1 .. dim, 3]), cornerPoints[1 .. dim, 3]], [seq(cornerPoints[1 .. dim, 4]), cornerPoints[1 .. dim, 3]]], align = {above, right}, font = [Courier, bold, 20])

I wanted to keep a running total over a number of independent batch mode Maple scripts.

So I figured I use .m file.   

Each run will read the old variable from .m file, update it, and write it again.

All what it need to do is just check if the .m file exist or not to account for the very first run.

But to my surprise, I found the variable content do not update after doing SAVE A,"TMP.m"

It seems Maple sees A variable already in TMP.m and does not save the new value of A again?. Just guessing. I was expecting that after I do  read "TMP.m" that the variable in the file will overwrite same variable value in the local proc. 

After one time update, each time I read the variable, its value is same.

First time using save myself, so may be I am doing something wrong but do not see it. I was expecting to see   10,20,30,40,50,..... running total, but I see 10,20,20,20,20,...../

What Am I doing wrong? do I need to make the variable global for this to work?

Here is worksheet. Maple 2024 on windows 10.

Download T.mw

Just found very serious problem.

Was trying my code in command line maple (cmaple.exe) only to find latex() command fails now.

Same code works with no problem in worksheet.  Here is first the worksheet version.
 

Download worksheet_version_latex_OK_june_21_2024.mw

Now I do same thing but from command line. I put the above code in A.mpl file in some folder on windows:

ode:=diff(y(x),x)=x;
try
    s:=latex(ode,'output'=string):
    print("Latex command worked on ode");
catch:
    error lastexception;
end try:


the_output:=Student:-ODEs:-ODESteps(ode,y(x)):
try
    s:=latex(the_output,'output'=string):
    print("Latex command worked");
catch:
    error lastexception;
end try:

Then opened a command windows terminal and cd to the above folder and typed this command

"C:\Program Files\Maple 2024\bin.X86_64_WINDOWS\cmaple.exe"  -q A.mpl

And this is what happens. Latex works OK on generating latex for the ode, but not for the steps!It gives error

Error, latex, invalid input: %1 uses a %-2 argument, %3 (of type %4), which is missing, latex:-ModuleApply, 1, e, anything

Also I was not able to suppress the display of the odesteps on the terminal even though they do not display in worksheet, they still print in the terminal. But this is a side issue.

Why does Latex gives error in command line? 

I think it is related to those funny looking characters (bullets?) signs at the start of each ODE step that show in the terminal? 

But in worksheet latex has no problem converting the ODE steps to Latex. It is only in cmaple. 

Is there a way to correct this? It seems to be some character encoding is causing the problem for Latex on command line vs. worksheet.

Windows 10, Maple 2024

Hi -- I have used this valuable platform many times to ask technical questions, but I am facing a particularly annoying problem in Maple 24 that did not exist in Maple 23. When I work on a Maple sheet and press Shift + Enter to move the cursor to a new line, an unwanted space appears. The issue is that when I use this combination twice on existing Maple sheets to create whitespace, the variable name often gets split up. Additionally, when I try to move back to the previous line to add something, I simply cannot. This issue did not exist in Maple 23 or any version since Maple 15. I have checked Tools > Options under both Display and Interface, but I have not found a solution. Is there a way to eliminate this annoying space?

  I would like to print my help pages to pdf. Is there a way to install A3 paper size. That would help in maintaining the layout as seen on the screen. 

Maybe there is an alternative approach.

How did Student:-ODEs:-ODESteps([ode,ic]); managed to get this zero solution to this ode? I can't follow the logic it did.

Any ideas what it is doing in the 4th step there?
 

Download strange_ode_steps_solution_june_20_2024.mw

Have a list of four projective points. I need to check that they are colinear projectively. If one point is at infinity i.e. 0 in z position I can chech if combination of cross product and dot product is 0.
a)  What is a good way to find if one ot the four has zero in z position?

b) Having found that is there a neat way of piching the next two/three points by making the count wrap automatically. e.g 3  then 4,5,6 i.e. 3,4,1,2

Download 2024-06-18_Q_4_points_projective_colinear.mw

I am getting Maple server crash each time running this solve command.

Could others reproduce it? I am using windows 10. Maple 2024.  Why does it happen?

Will report it to Maplesoft in case it is not known. Worksheet below.

Download maple_crash_calling_solve_june_18_2024.mw

This bug seems to have been introduced in Maple 2023 since it crashes there also.

But not in Maple 2022. No crash there. Same PC.

Download maple_NO_crash_calling_solve_june_18_maple_2022.mw

odeadvisor says that this ode is _homogeneous, `class A`, but I am not able to verify this. Also when asking dsolve to solve it as 'homogeneous' it returns no solution. 

This type is described in https://www.maplesoft.com/support/help/maple/view.aspx?path=odeadvisor%2fhomogeneous

Here is worksheet with my tries.

Would someone be able to confirm if this is really an _homogeneous, `class A` ?

my own code checking says no.  But if it is, then why dsolve do not solve it when asking it to use homogeneous method? Is the method I asked it to use it do not apply to class A?

Download checking_homogo_ode_type_june_18_2024.mw

Hello guys, I am doing the numercial error analysis study, but now I meet such problem:
how to change the 2d dot plot to the 3d plot? I mean extending like the generatrix of a cylinder.
It can be understood as the inverse operation of projecting a three-dimensional xyz surface onto the xy plane. the code is attached. Welcome all you discuss.

I use one engine per one worksheet. So one would expect that doing restart; command; to always behave the same way. Right?

Because each time, new or refreshed mserver.exe is used.  But here is a worksheet, where I run it few times (all with restart each time), where sometime the command timelimit hangs, and sometime does not. I do not mean it takes little longer sometime. I mean completely hang.

I've waited 10-20 minutes and nothing happens. And sometime I saw it return back in 2 or 3 minutes. But most of the time it hangs.

I wish someone could explain this to me. If it hangs each time, or not hang each time, I can understand. (ofcourse timelimit should never hang, as it was supposed to have been fixed in 2021, but this is separate issue).

But why it hangs sometimes and not other times? Does Maple use some sort of random number generator inside it to decide on things? For me, software should behave the same each time when run from same initial state.

It also depends on the amount of timeout given if it hangs or not.

What can cause this different behavior and most important, what can one do to make it behave same way each time? I thought that what restart supposed to do.

Any insight what can cause this is welcome.

I also found that closing the worksheet completely and opening it again, results in different behavior in the timing. It looks like restart does not clear everything, as what happens when closing the worksheet and reopeing it again.

i.e. Sometimes when it completes and not hang, then issuing restart again and running the int() command, it will also not hang most likely.

It seems Maple have remembered something. But closing the worksheet and opening it again, it will hang again most of the times.

The point of all this, is that Maple behaves differently each time. But why??

Download hangs_int_june_16_2024.mw

Here is one screen shot of one of those times where it returned back. Took little over one minute. Good.

Here is second screen shot where it took about1,800 real time seconds to return. (30 minutes, even though timelimit was one minute). Same exact code.

update

I tried the suggestion given below to use _EnvProbabilistic:=0 but it had no effect on making Maple behavior consistent each time.

Below worksheet shows this. I tried 6 trials, each with restart. 

First trial it timeout at 74 second. good. Second trial took 1403 seconds !  Third trial went back to 74 seconds again (good).  Trial 4 took also took about 74 seconds (good). trial 5 went back to being slow and took about 1400 seconds again. Trial 6 went back to being fast and took about 74 seconds.

So the pattern seems to be 

                     fast SLOW fast fast SLOW fast.....

But I also tried this whole test again, by closing the worksheet and opening. Now the pattern changed to

                     SLOW fast fast fast SLOW SLOW ....

I also attached the worksheet for the above below.

So Maple still behaves in random fashion in doing the integration above. sometimes it is slow, sometimes fast. All using same exact code and same integral. Extra points to anyone who could find out why and how to fix this.  

This worksheet have pattern    fast SLOW fast fast SLOW fast....

Download hangs_int_V2_june_16_2024.mw

This worksheet below have pattern      SLOW fast fast fast SLOW SLOW ....

Download hangs_int_V3_june_16_2024.mw

Observation: When it finishes fast, timeout is always in  PDEtools/NumerDenom.

When it takes long time, timeout is always in sdmp:-mull

Any other suggestions what to try are welcome.

Is this a valid behvior by int?   

int(A,x,method=_RETURNVERBOSE) hangs.

But  int(simplify(A),x,method=_RETURNVERBOSE) returns in few seconds with "default" result same as int(A,x)

Should this have happen? I try to avoid calling simplify unless neccessary because it can add csgn's and signums and so on to the result. 

But the question is: Should one really need to simplify the integrand to get the result in this example? Does this mean one should call simplify on the integrand to avoid the hang that can show up? 

This only happens when using method=_RETURNVERBOSE 

Just trying to find out if this is normal behavior and can be expected sometimes.

Download why_int_hang_unless_simplify_june_15_2024.mw

odetest should be made more robust.

Here is an example where the same exact solution and same exact IC, but when solution is just writtent in a  little different form, odetest no longer verifies it.

Do you consider this a bug? How is the user supposed to know their solution is correct or not now, since it depends on how it is written? What can a user then do to help odetest in this case verify the solution?

Download same_solution_not_verified_june_13_2024.mw

Maple gives same solution for two different equations.

eq1 := 1/5*sqrt(-20*y + 1) - 1/5*ln(1 + sqrt(-20*y + 1)) = x + 2;
eq2 := -1/5*sqrt(-20*y + 1) - 1/5*ln(1 - sqrt(-20*y + 1)) = x + 2;

Solving these for y, gives same exact solution. But this is not correct. As this worksheet shows.

Is this a bug? How could two different equations give same solution?
 

Download different_equations_give_same_solution_june_12_2024.mw