MaplePrimes Questions

I want to solve my PDE using Homotopy Perturbation Method. I have error while solving i dont know why it is showing error. If anyone knows the what mistake i have done in the code, kindly correct me. I want to find the equation of W(r,z) . dp/dz is a pressure terms which is independent of r. And the initial guess is taken as w0 := (-eta^2 + r^2)/2.  Help me to solve this.

 

 

restart;
PDEtools[declare](w(r, z));
               w(r, z) will now be displayed as w

N := 1;

w0 := (-eta^2 + r^2)/2:
w(r,z) := sum(p^i*w[i](r, z), i = 0 .. N)
                   w[0](r, z) + p w[1](r, z)

HPMEq := (1 - p)*diff(w(r, z), r $ 2) + p*(diff(w(r, z), r $ 2) + diff(w(r, z), r)/r - (1 + lambda)*(dp/dz + A2*M^2*w(r, z) + A1*w(r, z)/Da - m^2*UHS*BesselI(0, m*r)/BesselI(0, m*eta) + A3*sin(Phi))/A1);
                                                                /
                                                                |
        // d  / d            \\     / d  / d            \\\     |
(1 - p) ||--- |--- w[0](r, z)|| + p |--- |--- w[1](r, z)||| + p |
        \\ dr \ dr           //     \ dr \ dr           ///     \

  / d  / d            \\     / d  / d            \\
  |--- |--- w[0](r, z)|| + p |--- |--- w[1](r, z)||
  \ dr \ dr           //     \ dr \ dr           //

     / d            \     / d            \                       
     |--- w[0](r, z)| + p |--- w[1](r, z)|      /             /  
     \ dr           /     \ dr           /   1  |             |dp
   + ------------------------------------- - -- |(1 + lambda) |--
                       r                     A1 \             \dz

         2                            
   + A2 M  (w[0](r, z) + p w[1](r, z))

                                       2                    
     A1 (w[0](r, z) + p w[1](r, z))   m  UHS BesselI(0, m r)
   + ------------------------------ - ----------------------
                   Da                   BesselI(0, m eta)   

                  \
                \\|
                |||
   + A3 sin(Phi)|||
                ///


for i from 0 to N do
    equ[1][i] := coeff(HPMEq, p, i) = 0;
end do;
                     d  / d            \    
                    --- |--- w[0](r, z)| = 0
                     dr \ dr           /    

                           d                                   
                          --- w[0](r, z)      /             /  
 / d  / d            \\    dr              1  |             |dp
 |--- |--- w[1](r, z)|| + -------------- - -- |(1 + lambda) |--
 \ dr \ dr           //         r          A1 \             \dz

                                          2                    
          2              A1 w[0](r, z)   m  UHS BesselI(0, m r)
    + A2 M  w[0](r, z) + ------------- - ----------------------
                              Da           BesselI(0, m eta)   

                 \\    
                 ||    
    + A3 sin(Phi)|| = 0
                 //    


NULL;
cond[1][0] :=  D*w[0](0,z) = 0, w[0](eta,z) = 0;
for j to N do
    cond[1][j] := D*w[j](0,z) = 0,w[j](eta,z) = 0;
end do;
               D w[0](0, z) = 0, w[0](eta, z) = 0

               D w[1](0, z) = 0, w[1](eta, z) = 0


for i from 0 to N do
    dsolve({cond[1][i], equ[1][i]}, {w[i](r,z)});
    w[i](r,z) := rhs(%);
end do;
w(r,z) := evalf(simplify(sum(w[n](r,z), n = 0 .. N)));
convert(w(r,z), 'rational');
w(r,z) := subs(r = 0, w(r,z));
Error, invalid input: rhs expects 1 argument, but received 2
                    w[0](r, z) + w[1](r, z)

                    w[0](r, z) + w[1](r, z)

                    w[0](0, z) + w[1](0, z)


 

I tried to change my email adress but after submitting changes I still get my old email listed.

Additionally to only changing the email I also changed my password.

Nothing worked. What could I have done wrong?

Hello everyone,
Is it possible to load complete Maple packages into Maple Flow?

Regards,

Oliveira

In the attached file, (6) is stated as "false." However, it is possible to prove with pen and paper that term1 = term2. In (5), the limit function is sought but not determined.
What am I doing wrong?test1.mw
 

restart

term1 := (2*cos(2^n*x)+1)/(2*cos(x)+1)

(2*cos(2^n*x)+1)/(2*cos(x)+1)

(1)

term2 := product(2*cos(2^k*x)-1, k = 0 .. n-1)

product(2*cos(2^k*x)-1, k = 0 .. n-1)

(2)

term3 := term1*(2*cos(2^n*x)-1)/(2*cos(x)-1)

(2*cos(2^n*x)+1)*(2*cos(2^n*x)-1)/((2*cos(x)+1)*(2*cos(x)-1))

(3)

simplify(term3)

(1+2*cos(2^(1+n)*x))/(1+2*cos(2*x))

(4)

limit((1+2*cos(2^(1+n)*x))/(1+2*cos(2*x)), n = infinity)

limit((1+2*cos(2^(1+n)*x))/(1+2*cos(2*x)), n = infinity)

(5)

is(term1 = term2)

false

(6)

NULL


 

Download test1.mw

 

Why can't the sys0 extracted using the convertsys command be processed with collect? However, when I extract its amplitude and then perform collect again, it works. Why is this happening? Is there a good method to handle this? I feel that copying it out is inconvenient for subsequent modifications.

nature_frequency_question.mw

I want to define a multivariate function f(x1,x2) and its gradient f1(x1,x2) in order to calculate

f(X)=f(X[0])+grad(f(X[0])*(X-X[0])

I try in this way:

with(LinearAlgebra);
f := x -> x[1]^2 + x[2]^2
f1 := x -> <diff(f(x), x[1]), diff(f(x), x[2])>
A := <2,3>
f(A)
     13
f1(A)
     Error, (in f1) invalid input: diff received 2, which is not valid for its 2nd argument
 

What is wrong and how could I define f1(x) in order to write f1(A) for the gradient of f calculated  at A?
Thanks

I created a temporary account because I could not log in after the recent shutdown of MaplePrimes.

The login issue is resolved and I do not need the temporary account any longer.

How can I delete the temporary account. Edit: deletion is not the primary objective. Making the account inactive would do as well.

I am probably overlooking this option

I intend to use LinearAlgebra package to do some calculations. I want to compute the basis for large Matrices. My discovery is that the linalg[kernel] command, which the document claims is deprecated, could do such computation significantly faster than the LinearAlgebra[NullSpace] command. For a 200 x 500 large random matrix, linalg[kernel] clocked 33 secs, while the LinearAlgebra[NullSpace] takes 200 secs, as shown in the worksheet NullSpace_vs_kernel.mw.

I wanna know what makes the difference, or is there a misuse for LinearAlgebra[NullSpace].


For years I used to use 2 accounts when I am home

  • one under Firefox corresponds to my profesionnal account, which I can access to from my office oror home (and which is the one I use here),
  • the other one under Safari is my "personal" account; (login mmcdara)  which I cannot access to from my office because of security rules.
     

To separate the managing of professional and personal accounts I always used the former under Firefox and the latter under Safari.
Since the outage my personal account is no longer accessible, neither from Safari nor Firefox.

I created this account about eight years ago using the adress michael.mcdara@gmail.com and during all these years the connexion to Mapleprimes from Safari was  "automatic" in the sense that I was always logged in as mmcdara. Even after having quit Safari or shut down my computer, I was logged in as mmcdara as soon as I reopened Mapleprimes (a curiosity, for quitting Firefox being logged in as sand15 and openening it again required my relogging as sand15).

This still was the case early this morning (I sent replied to andiguy) but not one hour after.
Indeed Mapleprimes asked me my mail adress, that I knew, and my password, that I have forgot, of course.

Eight years ago the double authentification was not mandatory and so Gmail has purely and simply made the adress michael.mcdara@gmail.com inaccesible in between (I used it only with Mapleprimes, thus no real need to look at it regularly nor to bother with this double authentification stuff... at least I thought).
So any attempt to ask for a reinitialization of my password is a dead end for I cannot access the address michael.mcdara@gmail.com


My main activity on Mapleprimes is realized using my mmcdara account.
What bothers me the most  (loosing my mmcdara account would be unplesant but I can survive this) is that I was working since several months on two or three posts and that I can't anymore access the corresponding drafts (not a deadly situation I cannot survive to neither).

Do you have any idea about how to solve these issues?
I would satisfy myself recovering the two or three post drafts I was working on.

Thanks in advance
 

Hi everyone,

I am trying to solve a system of coupled ODEs numerically. My worksheet runs and produces results, but when I look at the graphs, it seems that the boundary conditions are not being satisfied correctly. Could anyone help me identify the issue and  fix my implementation?

BCs_help.mw

I need to export an image in high resolution in JPEG, JPG, and PDF formats. Right now, I'm using screenshots, which results in low clarity. Could you please help me with the correct syntax to generate a high-resolution, downloadable image in these formats? I'm attaching the file below:

q_new.mw

Hi

I'm trying to duplicate this graph in Maple. Any suggestions on how to place the textplot labels (n=0, n=1, etc.) to the right of 0.8, just like in the original graph?

how to place the textplot labels (n=0, n=1, etc.)

Thanks

S7MAA_Dveloppement_Limit.mw

I came across this

Can these library components be used to perform FFT on signals in MapleSim?

Any guidance on FFT and MapleSim appart from exporting to Maple would be very much appreciated.

(Easy) frequency analysis is among the top features I am missing in MapleSim.

I constructed a density function, and I am certain it shows me what I want.  The problem I am having is parsing the Elliptic functions. Is there a way to "get rid" of the ones I don't want or need.

I generated a plot of the function -- the plot tells me what I expected based on simulation. I need to know if there is a way to express the density function (y) as a function of t and without the elliptic functions..  Even a numerical solution would be fine.

I assume the denomenator term is correct. I also assume that I don't need complex values. My input file is below.

Basics.mw

I have set a style for my Maple 2023 sheets

2D-Input, Font: Times Roman 28 pt.

In the the past when I reopened the file, it would come back with the same 2D input font.

Starting today, when I reopen the file, the whole sheet is changed to. 

Maple-Input, Font: Courier New 12 pt. 

You can see it flash on the original stylem then reset to the Courier font. 

I tried resetting the Display options, but no luck.

Any thoughts?

1 2 3 4 5 6 7 Last Page 1 of 2424