with(DifferentialGeometry):with(JetCalculus):
DGsetup([x],[u],E,5);
vars≔x,u,u[1],u[1,1],u[1,1,1];
PDEtools[declare](Q(vars));
TotalDiff(Q(vars),x);
TotalDiff(u[1,1],x);

Hi everyone,

Recently I came across the total differentiation command in the PDEtools. For its

documentation, I used the following link

http://www.maplesoft.com/support/help/Maple/view.aspx?path=DifferentialGeometry/JetCalculus/TotalDiff

Unfortunately, when I try to replicate this it did not work as expected. I am getting the total derivative of the expression to be zero. I do not understand where I am going wrong.

You can find my code above. I am also attaching the screen shot of my maple file.

I would really appreciate if someone could help me out. Thanks for your help.

is there a possibility to display the partial derivative of f(x,y) wrt. y as

and second order / cross-partials accordingly?

thx

jo

I have created several animated 3-d figures using Maple.  Exporting an animation as a gif file I find that with, for example, Quicktime, I can run the animation. However I cannot rotate the 3-d figures using Quicktime.  Is there some other way to make such animations available to people not having Maple, so they can rotate the figure as well as run the animation? I would appreciate any ideas about this.

The following program hangs on the last command and a hard restart is required. The computation of a 2 x 2 matrix times a 2-vector is not that hard. Any ideas as to what is happening?

Another question: if v is a vector that depends on x and y say why does
>solve(v=0,{x,y})
not work?

It should only take a few lines of code to change v=0 to the system {components of v = 0}

I have been using Maple for many years and have created many Maple procedures for my own use in different projects. My usual practice is to place the procedures in a .txt file using WordPad or NotePad on my Windows machines. Then to load, for example, a file named C:\Users\Ed\Desktop\Top Quandles\Procedures.txt I use the command 

read("C:\\Users\\Ed\\Desktop\\Top Quandles\\Procedures.txt");
or
read("C:/Users/Ed/Desktop/Top Quandles/Procedures.txt");

Or I can leave the path off if the file is in the same folder as my worksheet.

This has always worked well for me. But have two questions:

1. Is there is a better way to save and load a bunch of procedures? Also I might mention that I frequently have to go into the file and change procedures or add new procedures, data, etc...

2. Recently I had occasion to send a worksheet and a txt file to a Mac user. We were not able to get the worksheet I sent him to read the .txt file on his Mac. Any suggestions on how to do that on a Mac? We tried putting them both in the same folder and just using a simple read("Procedures.txt"); command but the Mac didn't like that.

Any suggestions about either of these two issues would be appreciated.

Thanks,

Edwin

Does anyone know if there is a simple way to write a falling factorial (pochhammer symbol) in Maple. It seems pochhammer is the rising factorial with no option to change to falling.

Thanks in advance.

I assigned

before an algebraic calculation so I would like to get  or have the program print the 70 digits of the answer and not just 10 digits. Because when I press ENTER, I get only 10 digits.

fieldplot is a wonderful tool for plotting vector fields. The option 'fieldstrength' is very useful to scale the arrows so that one can better visualize the field. I often use fieldstrength=log.

However, if one includes the RealDomain library, the fieldstrength=log option fails. I don't see why it should. Can someone enlighten me before I report this as a bug.

Hi all, 
I was only wondering if there is a way how to trunk a solution using a maple command.

I want to use it to give a truncation error which is equal to :(14/45)(D^5)(y)(0) h^5

The result I am getting is as followed: (it is correct, I just want to cut off the bit with the power of 6)
........
......
>error:=expand(Yx[i+1]-Yx[i-3]-(4*h/3)*(2*f[i-2]-f[i-1]+2*f[i]));
                          
          error :=  (14/45)(D^5)(y)(0) h^5  + 7/10 (D^6)(y)(0) h^6
                  
thank you in advance

Hi, 

I'm being unable to plot the solution to the equation

schro := {-(diff(psi(x), x, x))+(2*a*b*x^4+a^2*x^6+(b^2-a*(2*p+3))*x^2-(2*p+1)*b)*psi(x) = 0};

for the special cases of a=b=1 and p=0 and p=1

I've used dsolve and am getting Heun functions :-(

The claim is that the solutions come out to be exponentials of the form:

psi(x)=(x^p)*exp(-(a*(x^4))/4 - (b*(x^2))/2)

thanks in advance

I am trying to implement Subresultant p.r.s. algorithm for calculating greatest common divisor. The algorithm decribed in the book:

My code return the correct GCD, however the sub-resultant terms are different from the result of the built-in function. The last term a[i-1] is huge and involves fractions. I think my implementation is same as the algorithm described in the textbook.

I have attached the file. Could anybody spot anything wrong in the code? Why do fractions still appear? In my code, "lsr" is last subresultant term returned from the built-in function, the second one is my result.

Download subresultant.mw

I am having difficulty to solve the following ODE

ode:=diff(R(x),x$6)=Dirac(x-y);

with initial and boundary conditions

bcs := ((D@@3)(R))(1) = 0, R(0)-((D@@5)(R))(0) = 0, ((D@@2)(R))(0)-((D@@3)(R))(0) = 0, ((D@@5)(R))(1) = 0, (D(R))(0)+((D@@4)(R))(0) = 0, ((D@@4)(R))(1) = 0;

I want to solve the above ODE for two cases 1) x>y and 2) x<=y

Thanks

Hello,

I want plot this equations with values independents x,A,B

But this is error.

Any idea?

Thanks

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

I need to implement gaussian elimination with cross multiply. I followed the method decribed in the textbook, however the result returned a wrong determinant. I noticed that cross multiplication changes the determinant in every step. Does anybody know how to use the cross multiplication without altering the determinant?