I resolved the coefficients to a 2nd order diff eq of the form:ay''+by'+cy=f(t)

I have included the .mw file for convenience at the link at the bottom of the page.  I resolved the coefficients in 2 different ways & they do not concur.  The 1st approach used the LaPlace transform & partial fraction decomposition.  The coefficient results are given by equations # 14 & 15.  The 2nd approach used undetermined coefficients where I assumed the particular solution and then applied the initial conditions to resolve the coefficients pertaining to the homogeneous solution which are given in the results listed in equation #23.  Noted in the 1st case the coeff's are A₃ & A₄ and for the 2nd approach the coeff's are A₁ & A₂.  I have worked this numerous times & do not understand why they do not concur.  So I thought I should get some fresh eyes on the problem to find where I may have gone wrong.

Any new perspective will be greatly apprecieated.

I had trouble uploading the .mw file so I have included an alternative link to retrieve the file if the code contents is illegible or you cannot dowlad the file drectly from the weblink  Download coeffs_of_homogen_soln_discrepancy.mw.  You should be able to download from the alternative link below once you paste the link into your browser.  If you cannot & wish for me to provide the file in some other fashion respond with some specific instructions & I will attempt to get the file to you.

https://unl.box.com/s/dywe90wwpy0t4ilkuxshkivz2z26mud8

Thanks 4 any help you can provide.

Download coeffs_of_homogen_soln_discrepancy.mw

Dear all,

I'm investigating the vibration performance of timber beams. I have sample data from my test which shows the vibration of the beam. I want to determine the eigenfrequency from this data. The problem I face is that I'm not finding the probber eigenfrequency. I have two data rows; time and amplitude. I'm able to plot the amplitude with SignalPlot but not the time, therefore I have to adjust the samplerate. I have the same problem with the fourier analysis. Is it possible to include the time period as well?

Regards,

Maurits

Dear all,

I need to transforme these equation from time domain to frequency domain with fourier transforms and solve it in frequency domain but i received the flowing error

any helps

thank you !

Code :

Download Fourier_TRAns_MAPLEprime.mwFourier_TRAns_MAPLEprime.mw

Hi, I'm trying to use Maple to construct some examples of symmetry solutions for certain nonlinear PDE's.  As a warm up, however, I'm working through the commands just for the heat equation in 3d: u[t]-u[x,x]-u[y,y]-u[z,z]=0 

I've gotten Maple to produce both determining equations for the symmetry infinitesimal generators via the DeterminingPDE command.  I've also gotten the command Infinitesimals to work too.

However, when I next use PDETools Invariants command, it correctly outputs invariants for most of the generator output of Infinitesimals EXCEPT it won't output anything for the simple rotation generators yd[x]-xd[y].  It will, however, output invariants if the rotation is between an independent and the dependent coordinate.

An example:
with(PDETools)
S:=[_xi[x]=y, _xi[y]=-x, _eta[u]=0]
Invariants(S,u(x,y))

*Above returns nothing, But if you instead have _xi[x]=x and _xi[y]=y then it returns the right invariants.

Thanks in advance!

Hey, this is not the I've had this encounter. I want to open this saved document but when I open it and Maple starts up it just hits me with "A problem was encountered while opening the workbook. Database is not opened". How can I get to open it properly and see my math notes?

How can this be prevented?

When I try to upload the file in this message it says "Cant open a null file"

Any help?

Jacob

plz code and sole that this integral!!!!!!!!!!

!!!

solve Derivative in maple

see in photo

What do people find a good screen size is? 

Personally I find two monitors would be ideal for using Maple and especially Maplesim.  I'm going to be adding a second monitor, probably a 20".  Maybe 24" is better?  I think 20" would be enough.  Just wondering how many monitors people out there work with and their monitor sizes.

Dear all,

I am creating an animation, and I was wondering if I can add a multiplier to my equation in a specific range.  So starting from z:=0.2 add a multiplier (z+1). The code I have so far is added. Does anyone know a code for this?

Kind regards

restart; 
with(plots); 
a := -1/2; b := 1/2; c := -2; d := 2; n := 20; 
g := proc (x) options operator, arrow; value(Int(sigma(t), t = 0 .. x)) end proc; 
sigma := proc (z) options operator, arrow; 2*sqrt(2*h^2-4*z^2)*z/h^2 end proc; 
h := i/n; 
for i to n do 
an2[i] := plot(sigma(z), z = -(1/2)*h .. (1/2)*h, view = [a .. b, c .. d], color = AQUAMARINE); 
an3[i] := plot(2*g(x), x = 0 .. (1/2)*h, view = [a .. b, c .. d], color = RED) 
end do; 
p := plots[display]([seq(an2[i], i = 1 .. n)], insequence = true); 
q := plots[display]([seq(an3[i], i = 1 .. n)], insequence = true); display(p, q)

> restart;

with(plots);

pr := .72; p := 0; n := [.5, 1, 1.5]; s := 0; a := .2; b := 0; L := [red, blue, green]; l := 0; k := 1;

for j to nops(n) do R1 := 2*n[j]/(1+n[j]); R2 := 2*p/(1+n);

sol1 := dsolve([diff(diff(diff(f(eta), eta), eta), eta)+f(eta)*(diff(diff(f(eta), eta), eta))+R1*(1-(diff(f(eta), eta))^2) = 0, diff(diff(theta(eta), eta), eta)+pr*k*f(eta)*(diff(theta(eta), eta))+R2*pr*k*(diff(f(eta), eta))*theta(eta)+(2*(a*(diff(f(eta), eta))+b*theta(eta)))/(1+n[j]) = 0, f(0) = 1, (D(f))(0) = b*((D@@2)(f))(0), (D(f))(1.8) = 0, theta(0) = 1+s*(D(theta))(0), theta(1.8) = 1], numeric, method = bvp);

fplt[j] := plots[odeplot](sol1, [eta, diff(diff(f(eta), eta), eta)], color = L[j], axes = boxed); tplt[j] := plots[odeplot](sol1, [[eta, theta(eta)]], color = L[j], axes = normal) end do; plots:-display([seq(fplt[j], j = 1 .. nops(n))]);

plots:-display([seq(tplt[j], j = 1 .. nops(n))]);

staganation_point1.mw
 

can we chage the axis sir ?? like  f'' vs eta to f'' vs lambda.

Download staganation_point1.mw

Hello every one,

I'm using Maple to create a compiled program of my model Maplesim. I had a error with "getcompiledProc" command, which is :

Error, (in GetCompiledProc) non-numeric initial condition for `Main.RAB.value`(t): Float(undefined)

the "Main.RAB.value(t)" represent a probe used to visualize an output of my system.

Does anybody had a such error ?
Thank you for your responses.

Larbi ANIBA

I am writing a package to define a few Records and collect some quantities and formulae to do some arithmetic with.

At some point I started running into a severe problem: Each time I want to use one of the exports form the module, the Maple kernel dies with a "Stack limit exceeded" message. The issue is: This seems to happen only on Maple 2016. I had some issues in Maple 2015 but that got sorted by rewriting some stuff. I never had any issue like that with Maple 15. I went as far as commenting out most of my .mapleinit code to make sure that did not cause issues. The code works as intended in Maple 15 and in Maple 2015.

I am posting this here and am asking others to see if they can reproduce this. Needless to say I will SCR this. But I actually need to get this to work.

The error can be triggered by simply entering

Booster;

after loading the package. Needless to say, it should just echo the name "Booster", to get more one would need to enter eval(Booster) (due to the last-name evaluation rules).

Thanks,

M.D.

BooMBA.mw

Hello everybody,

I want to solve this pde.the desire solution is V(r,z). three boundar conditions are written that two of them are related to rhe radial and one is related to the longitudinal coordinate.

I attached the solution for you. but this solution is derived by Matlab. Now, I just want to resolve it by Maple, but I couldn't reach it. Please let me know the correct way asap.

Thanks a lot.PDE.mw
 

Download PDE.mwPDE.mw

Howdy!!

Just thought I'd put a quick one in. I'm trying to solve the Schrodinger equation given as:

under the constraint

I'm trying to plot this for a range of values of the parameters a,b and fixed p=0,1.

I'm aiming to get a solution of the form

and plotting it.

Thanks in advance

Recently I have used a FilterForge filter to generate hyperbolic tiles from images (Lua code with Möbius transform etc. available). If an input image (1 see below) is selected a tile (2) is generated if the hyperbolic parameters (5,3,2) were chosen.  How could this be made with Maple?