Maple 2018 Questions and Posts

These are Posts and Questions associated with the product, Maple 2018

Is possible to solve this differential equation by maple?

thaks...

Hi,

I'm using the eBookTools package to convert a .mw file as a chapter into a PDF file. However, a problem arises when I convert a document with a few repeated plotting commands (such as plot(x^2)). The issue is that in the final PDF the images of the various plots overlap, and that the individual plots can't be clearly seen. Is there a resolution to this?

Thanks,
Bart

Is package SumTools supposed to be a superset of the sum command in Maple? Or is it supposed to be a complementary to it? When should one use SumTools vs. sum?

The help on SumTools says

The SumTools package contains commands that help find closed forms of definite and indefinite sums. The package consists of three commands and three subpackages.
 

But does not make it clear when to use it vs. sum or what is its relation to sum command.

I am asking because on one example, sum is able to give an answer, while SumTools can't. I have expected the other way, where if sum failed, then one will try SumTools.

restart;
sum(1/n*sin(n*x),n=1..infinity) assuming 0<x,x<Pi

SumTools:-IndefiniteSummation(1/n*sin(n*x),n=1..infinity) assuming 0<x, x<Pi

 

 

This is using Maple 2018.2.1 and using Physics version MapleCloud 289 on windows 10, 64 bit with lots of RAM (64 GB). The call to timelimit hangs. Is there a workaround?

restart;

#and in new execution cell

pde :=  diff(w(x,y),x)-((k+1)*x^k*y^2- a*x^(k+1)*tan(x)^m*y + a*tan(x)^m )*diff(w(x,y),y) = 0;
cpu_time := timelimit(180,CodeTools[Usage](assign('sol',pdsolve(pde,w(x,y))),output='realtime'))

 

 

 

 

Hello,

I'm a long-time Maple user and have used the CodeGeneration package in the past, but with a recent download of Maple 2018, I'm now getting an error I have never gotten before. Even when I do something simple (see below, for example), I get an error that reads "Error, (in clear) argument `` is incorrect or out of order". And I get this error no matter which language I choose. Any help would be much appreciated.

> with(CodeGeneration)

> R(exp(x))

Thanks!

 

 

how I can find solutions for non linear equations.

I want to find non zero solution.

thank you

ZAH.mw



Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/ZAH.mw .
 

Download ZAH.mw

how i can solve the eqution by ritz methode codes?

Here is a simple procedure that works fine if entered using 1D Maple input
> Q:=proc(x)
sin(x)
end proc;
but if you use 2D math input
> q:=proc(x)
sin(x);

  end proc;

Error, unterminated procedure
    Typesetting:-mambiguous(qAssignTypesetting:-mambiguous(

      procApplyFunction(x) sinApplyFunction(x),

      Typesetting:-merror("unterminated procedure")))
Error, unable to parse
    Typesetting:-mambiguous(  Typesetting:-mambiguous(end,

      Typesetting:-merror("unable to parse")) procsemi)

Ouch! But to confuse things further the following procedures may be entered using 2D math and work fine:
>H := proc (x) x^2*sin(x) end proc;
>K := proc (x) sin(x^2) end proc;
Doesn't make any sense to me. Perhaps 2D math is not ready for prime time?

 

Hi!

I have a rather long Maple code and want it to be executed multiple times with a parameter changed each time.

Surely this can be done with the loop structure, but it seems the whole loop structure must be contained into one single execution group, which makes it to be a little inconvenient, since the code is too long.

 

So is there any alternative way to realize this utility?

 

Best regard and thanks!

This is not a problem per se, but more to understand the background.

restart;

f := polylog(2, -x);

int(f/(x+1), x);

convert(f, dilog);

int(%/(x+1), x)

 

The integration of the polylog maple is not capable of doing, but after converting to dilog it finds an anti derivative.

That leads to the question, why is dilog as a separate to polylog(2,*) implemented anyway? Why couldn't it all be done with the more general polylog function?

 

I'm also wondering why maple has difficulties to integrate

int(dilog(x+1)/(x+a),x)

for general a.

Using Maple 2018.2.1, I'm receiving a lost kernel message when importing the attached data file with ImportMatrix. I traced the issue to a "*" symbol at the end of the file but would have expected this to cause an error message (if any error at all) instead of the connection to the kernel to be lost. Is this a bug or am I misunderstanding the usage of ImportMatrix?

test.mw

test2.txt

I'd like to view the Maple source code in .maple file. I am not able to find how to do this.

I tried commands in 136697-Can-One-Get-The-Source-Code-Back-From

which applies to .mla using the march command. But it did not work for .maple. It gives an error when trying it on .maple file.

I can open the .maple file in the Maple user interface OK using File->Open

but other than documentation, I see no Maple code.

I am looking now at Physics updates file, which can be downloaded as .maple file from 

https://maple.cloud/app/5137472255164416

Since most Maple code can be viewed, I assume one can also view the source code in the above.

Any idea how to do this?

trying some examples from 209970-Exact-Solutions-For-PDE-And-Boundary--Initial-Conditions-2018

I noticed some answer change when adding assumptions which should not really cause the answer to change. Numerically, both answers seem to be the same. But one is series solution and the other with assumptions added uses integrals.

In wave pde on string where left end at x=0 and adding assumptions x>0,t>0 to pdsolve should produce the same form and it does on some problems but no on others.

Compare

#example 19, wave pde, on string left end fixed, right end moving, with source, no initial velocity
restart;
pde := diff(u(x, t), t$2) = 4*diff(u(x, t), x$2)+(1+t)*x;
bc := u(0,t)=0,u(Pi,t)=sin(t);
ic := u(x,0)=0,eval(diff(u(x,t),t),t=0)=0;

sol:=pdsolve([pde, bc,ic],u(x,t));  #1
sol:=pdsolve([pde, bc,ic],u(x,t)) assuming t>0; #2
sol:=pdsolve([pde, bc,ic],u(x,t)) assuming x>0; #3
sol:=pdsolve([pde, bc,ic],u(x,t)) assuming t>0,x>0;  #4

(1,2,3) above give same answer which is 

but (4) gives

Tried random points and numerically they are the same (set the sum to n=100 to evaluate).

my question is why would adding no assuming, or adding t>0 on its own or adding x>0 on its own give same answer, but adding  t>0,x>0 at same time give such a different looking soution.

I typically adding such assumptions to be safe, but here it seems to had some side effect I have not noticed before.

Physics:-Version();
 "C:\Maple_updates\Physics+Updates.maple", 2018, December 22, 

    10:41 hours, version in the MapleCloud: 265, version installed in this computer: not installed

kernelopts(version)
  Maple 2018.2, X86 64 WINDOWS, Nov 16 2018, Build ID 1362973

 

I try to solve ODE with conditions, but it give answer only without conditions:

SOT.mw

Thank you.

Dear authors,
How to solve this ode problem.

Download link ode.mw

In this problem the boundary condition is

Note: F=g in our problem.

eta approaches N.

Thank you.

 

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