I want to to solve the system of partial differential equation using maple. I tried it but I am not able to solve it ... please help.

the equations are as follows

Download Finding_transformation_eqn_between_zero_and_harmonic_with_conformal1.mw

Hi,

I am trying to solve a differentiation but I think I am stuck since the solution is not what it should be.

So, I got the equation below

eq4 := `S__2 ` = sin(alpha - phi)*sin(-beta + alpha)*H^2*M/(2*sin(-beta - delta - phi + alpha)*sin(beta)*sin(alpha)) - S__1

And according to the paper I read, to get the maximum value of alpha for maximum value of S_2, I need to make differentiation to first derivative where dS_2/d(alpha) = 0

Then I should substitute back value of alpha to equation above and the paper shows that i should get equation below.

`S__2 ` = 1/2*M*K__a*H^2 - `S__2 `

where K_a is

`K__a`= [(sin(beta+phi))/((sin(beta))/(sqrt(sin(beta+delta))+(sqrt(sin(phi+delta)*(sin(phi-varepsilon)))/(sin(beta-varepsilon))))]

I know its really hard but hope someone can give some idea how to do it.

Thank you very much.

Kind regards

Faiz Farhan

Got a lot of worksheets who are not complete anymore once opened in maple 2020

It can be only opened with a old version of Maple
Can it be imported in Maple 2020?

example 

Dynmod03.mws

Please can you help me in resolving this error?

Here is the codeOptimal_control_model_of_DF_and_LP_2.mw

I am currently working on a project that generates a set of matrices and I want to find their eigenvalues, but using the inbuilt Maple engine takes too long. The problem is that whenever I try to use the Matlab[eig] command I get the error:

Error, (in Matlab:-setvar) unable to store '-3.*Re(X)' when datatype=float[8]
I found out that solving symbolic matrices in MATLAB requires first defining symbols with the "sym" command but I've been unable to do that in Maple.

Hi, 

Could anyone help me to numerically solve this ode?
I've tried almost all the methods Maple proposes, trying to adjust stepsizes, tolerances and so on;, always without success.

I give also the exact solution of this ode in order to compare the numerical solution to.

Thanks in advance
 

Download Unsuccessful_dsolve.mw

I am creating Maple figures that are being used to create camera-ready figures in Adobe Illustrator. The graphic artist doing the Adobe Illustrator has asked me if there is a way to have the text information in the figure (tickmarks, axis labels, ...) saved as text and not created as an image?

I know that other EPS files have text stored this way, but it appears Maple does not do this. I can't find any documentation about this. Does anybody have any knowledge or experience about this?

Thanks in advance,

Doug

.............................................................................

In my worksheet today my intention was to compare the least squares linear regression for three datasets as indicated, but when I right click on the output as seen in the bottom line to select the plot type, all options state there to be independant variables K[0] and K[1], where as the output displays only the variable K as I intended, which part of my code is creating this confusion for maple?

Download ask_maple.mw

I want to do the substitution f(t) - ff(t) = epsilon for any variable t in Maple:

expand(myerror);
    2 f(x - 2 h)   f(x)   3 f(x + 3 h)   2 ff(x - 2 h)   ff(x)
  - ------------ - ---- + ------------ + ------------- + -----
        15 h       6 h        10 h           15 h         6 h

       3 ff(x + 3 h)
     - -------------
           10 h     

NULL;
myfunc := t -> f(t) - ff(t) = epsilon;
 myfunc := proc (t) options operator, arrow, function_assign;

    f(t)-ff(t) = epsilon end proc

algsubs(myfunc(t), myerror);
          2               1        3            
        - -- f(x - 2 h) - - f(x) + -- f(x + 3 h)
          15              6        10           
        ----------------------------------------
                           h                    

               2                1         3             
             - -- ff(x - 2 h) - - ff(x) + -- ff(x + 3 h)
               15               6         10            
           - -------------------------------------------
                                  h                     

NULL;
subs(f(-h*n + x) = 1, ff(-h*n + x) = 0, f(x) = 1, ff(x) = 0, f(h*m + x) = 1, ff(h*m + x) = 0, myerror)*epsilon;
                           4 epsilon
                           ---------
                             15 h   

This happens each time I run a long loop.  (2,500 iterations, which takes about 3 hrs to complete)

Maple always hangs (it does not time out on odetest() ). But my question is not about this (as this is something I have to deal with for long time now and mentioned it before many times. May be one day Maplesoft will fix this). 

But I noticed this also.  When Maple hangs, (and it always hangs at least once during this loop), I then click on the button "interrupt the current operation". This does stop the hangs.

Next I do a restart and starts the loop from the loop counter where it hanged in order to continue.  

But It still hangs at that same iteration. I repeate this again, and it still hangs.

Now I close Maple altogether, start Maple again, open same worksheet, and repeat from the same iteration again from where it was at before, now it does not hang.

This tells me that restart and "interrupt the current operation" do not clean everything as expected. Else why only restarting Maple makes it work?

It means mserver.exe (separate process from the frontend) still is caching something related, and that is why it hangs at that iteration.

I can reproduce this each time I run the whole loop from the start.

I can't make a minimal example, since I have no idea where it hangs and why. And it is related to running a long loop.

I just know it hangs when doing odetest() with timeout which never timeout, and it seems random at what iteration it decides to hang.

But my question is really basic here: Does mserver.exe keep any information about the earlier user session/worksheet even after restart ? help says that restarts clear internal memory of the kernel.

Isn't mserver.exe  the Maple kernel? If so, then what could explain that only restarting Maple clears the hang? I am just looking for ideas that could explain this.

This type of problem is the most annoying thing about Maple for me. 

Maple 2020.1 on windows 10.

Eigenvector result is changing every time it run.

How to make eigenvectors result the same every time it run?

What do I need to do to the "2 + 3" in the attached Document in order to make it evaluate? I know about F5 to switch between Text and Math modes, but that's not enough to get me where I want to be. The "2 + 3" is already in Math mode, but that's not enough to get it to evaluate.

The Document: t.mw

Something goes wrong in this worksheet with old code

Must be corrected
Thanks

fmatrix.mws

Anyone maybe helps me with writing the maple code mentioned in the following pdf.

I want to know about the potential flow around 3D domain.

Doc1.pdf