MaplePrimes Questions

Dear all,

I have the following question, this code:

restart:
with(DifferentialGeometry):
DGsetup([w1,w2],N):
eq1 := ExteriorDerivative(w1);  
eq2 := ExteriorDerivative(w1) &wedge ExteriorDerivative(w2);
eq1 &wedge eq2;

Gives the error:
Error, (in DifferentialGeometry:-Tools:-DGzero)  given degree, 3, exceeds that of frame dimension, 2

Unfortunately, I am not so familiar with differential geometry but as far as I know dw1 \wedge  (dw1 \wedge  dw2) = 0 should be correct.

Thank you for your help
best
baustamm1

Hi

 

I have an ODE which is based on a seperate function, and I would like to make a plot with the information

dsolve([diff(X(W), W) = (0.536000000000000e-3*(1-X(W)))*(1+X(W)), X(0) = 0], numeric)

and

C_A:= C_A0*(1-X(W))*(1+X(W))

which has been used as part of the ODE.

I would really like to plot C_A as a function of W. I have no problem plotting X as a function to W using odeplot. Ideally I would like to plot C_A and X vs W in the same plot.

Regards

Hello,

I would like to study the period doubling bifurcation behaviors of autonomous ODEs.

Although I know how to plot the Poincare section and bifurcation diagram for non-autonomous ODEs, such as Duffing oscillator, I totally stuck at the autonomous ones. Could you please help me.

It could be greatly helpful if you could share me the code of bifurcation diagram for, say, Rossler or Lorenz systems? 

Thank you in advance.

Very kind wishes,

Wang Zhe

I have a document containing notes from my past semester, which will not open properly. When i try to open up the document maple asks if i want to retrieve the content as plain text, 2D-math or maple input. The document is written in document mode and contains both text and 2D math. When I try to open it in plain text, maple gives me nothing, and with the two other options, maple is just loading forever. Can anybody help me retrieve the content og fix the document?

Noter_til_matematik_1.mw

I am teaching math i high school and we are using Maple. 

A lot of times the students forget to save their work. This is a problem if it is during a test, and the computer runs into problems.

The problem is that their document is called Untitled and i have a problem finding the file. 

The file that Maple usually creates is MAS.BAK file, but when they forget to save, I can't seem to find anything. 

The problem occurs in both MAC computers as well as PC.

Can anyone help.

 

While exploring a relatively simple sin equation, depending on how I process I get different forms of the root. Numerically, they appear to be the same, but I am having difficult figuring out how they could be, and would appreciate some guidance.

The more standard root is

21*arccos(RootOf(448*_Z^7+192*_Z^6-784*_Z^5-288*_Z^4+392*_Z^3+108*_Z^2-49*_Z-6, index = 2))/Pi


The less standard approach is

-(21*I)*ln(RootOf(7*_Z^14+6*_Z^13+6*_Z+7, index = 2))/Pi

Both of the RootOf appear to be irreducible, and it is not clear to me how you could transform the more complicated degree 7 polynomial into the simpler degree 14 polynomial while still retaining exactly the same roots?

If the equivalence holds up then it would be much easier for me to generalize the second form than the first.

I was, by the way, looking at minimizing sin(2/7*Pi*x) _+ sin(1/3*Pi*x) over its first complete cycle, as part of working up to a general rule for minimizing sum of sin of different amplitude and periods. diff(), then standard form is solve(), and less standard form is solve() of convert/exp() of the diff()

 

I am working with Euler's eqns. of motion. So want to animate the solution. I could do a simple set of spheres along the x, y, z axes  that represent the body or use an imported STL file.  Looking for some guidance on how to approech this. I can import an STL ok. How do I give it an xyz set of axes and then rotate/move these in an inertial frame? I have the equations and solutions already. A reasonable example would be adding an STL of a pendulum to http://www.mapleprimes.com/questions/220957-Non-Simple-Harmonic-Pendulum-Motion#answer235955  to Preben's animation response to a recent post  I placed.

 

I'm doing an interactive component and i need to plot a function and some points (which can change).
My question is if is it possible display the graphic with a value of automatic Plot Ranges.
For example the graphic would started with the first point and finisched with the last, like in this image (but i did it manually).

I want a sort of autozoom.

Enrico

how i can save results on text file from pdsolve?

 

thanks

maple11.mw
 

PDE := diff(u(y, t), t) = diff(u(y, t), y, y)-0.9e-1*(diff(u(y, t), y, y, y, y))

diff(u(y, t), t) = diff(diff(u(y, t), y), y)-0.9e-1*(diff(diff(diff(diff(u(y, t), y), y), y), y))

(1)

IBC := {(D[1, 1](u))(0, t)-0.9e-1*(D[1, 1, 1, 1](u))(0, t) = 0, u(0, t) = 1, u(100, t) = 0, u(y, 0) = 0, (D[1, 1](u))(100, t) = 0}

{(D[1, 1](u))(0, t)-0.9e-1*(D[1, 1, 1, 1](u))(0, t) = 0, u(0, t) = 1, u(100, t) = 0, u(y, 0) = 0, (D[1, 1](u))(100, t) = 0}

(2)

 

 

 

 

``

 

pds := pdsolve(PDE, IBC, numeric, u(y, t), spacestep = 1/5, timestep = 1/5)

_m2865547563008

(3)

 

     

   

NULL

_m2865547563008

(4)

 

 

fname1 := "C:/Users/test/Desktop/txtop1.txt"; seq(fprintf(fname1, "%12.8f, %12.8f\n", y, u(y, .1), y = 0 .. 10, 1)); fclose(fname1)

Error, (in fprintf) file or directory does not exist

 

p1 := pds:-plot(t = 0):p2 := pds:-plot(t = 1/10):

plots[display]({p2}, title = `\` profile at t=0,0.1`)

 

NULL


 

Download maple11.mw

 

Hello everyone, I use physics package and I input:

with(Physics)

Setup(mathematicalnotation = true)

Coordinates(X)

Setup(tensors = A[mu](X))

PDEtools:-declare(A(X))

PDEtools:-declare(p0(X), pm(X), pp(X), pt(X), Un(X), Ucn(X))

pt := proc (X) options operator, arrow; Matrix(2, 2, [[p0(X), sqrt(2)*pp(X)], [sqrt(2)*pm(X), -p0(X)]]) end proc

U := proc (X) options operator, arrow; Matrix(2, 2, [[1, 0], [0, 1]])+I*pt(X)*(1/f)-pt(X)*pt(X)*((1/2)/f^2) end proc

Ucn := proc (X) options operator, arrow; Matrix(2, 2, [[1, 0], [0, 1]])-I*pt(X)*(1/f)-pt(X) . pt(X)*((1/2)/f^2) end proc

And after that I write:

Trace(-LeviCivita[mu, nu, rho, sigma] . Ucn(X) . ((1/6)*e*A[nu](X)+M5*KroneckerDelta[nu, 0]) . Matrix(2, 2, [[1, 0], [0, 1]]) . Uсn(X) . d_[rho](Un(X)) . Uсn(X) . d_[sigma](Un(X)))

But I get an error:

Error, (in unknown) invalid subscript selector

Thanks for the help.

 

Dear all ;

I have a Partial differential equation

restart; with(PDEtools);

pde[2] := (diff(u(x, y), x))*(diff(u(x, y), x, x))+diff(u(x, y), y, y);
    where x and y in the square [0,1]

with boundary condition 

bc[2] := u(0, y) = 0, u(1, y) = 0, u(x, 0) = 0, u(x, 1) = 0;

Is there a simple code to compute the solution

Many thanks for any help

 

 

 

I am looking for persons with experience in setting up maple for the blind. The setting is a 21-year old blind
 student who wants to do math. He uses Mac OS/X and the built-in VoiceOver screen reader, plus refreshable Braille display (one-line), a Braille printer, and Nemeth, the Braille extension for math symbols.

Initially, we are working from no experience whatsoever, trying ideas, mostly failure. Getting some advice from persons who are blind and using maple would be wonderful. If anyone knows of an instance, a person who is blind and regularly uses maple, then we would both would be delighted to receive advice on what to install, how to set it up, and how to use maple on a daily basis.

One trouble for the VoiceOver screen reader is verbosity of maple output. Any methods to reduce the amount of output would be welcome. To uderstand the issue, look at the output of these two commands when interface(prettyprint=0) has been set to help out the VoiceOver screen reader:

matrix([[1,2],6,7]]); Matrix([[1,2],[6,7]]);

The first outputs the same text, which VoiceOver will read accurately. The second dumps out two lines of extraneous and confusing information, only 20% of which is useful. The verbosity is not restricted to matrix packages linalg or LinearAlgebra. It is a problem wtih nearly all packages.

-Grant Gustafson, Salt Lake City, Univ of Utah Math Dept

 

 

Hi,

I have a Maple code which produces an output plot for a first order differential equation,

nde := evalf(subs(npar, de));
nds := dsolve({nde, sigma(0) = -1e-8}, sigma(t), type = numeric);
acc_nds := (sig0, ae, re) -> dsolve({nde, sigma(0) = sig0}, sigma(t), type = numeric,
method = lsode[backfull], abserr = ae, relerr = re, maxfun = 0, ctrl=Ctrl);

odeplot(acc_nds(-0e-7, 1e-13, 1e-13), [t, sigma(t)], t = 0..2);

This produces the outputplot that I need for sigma(t). I need to produce a outut for d(sigmat)/dt, and how can this be done? what is the command I should use?

Additionally, how can i get the data set out of the polt in to a excel file or a text file?

I am quite new to maple, so i expect your kind support

Thanks

I have read the doumentation on adding generic hints or feedback to a problem. However, what I would like to do is create adaptive hints that are triggered when a student enters a particular type of answer. I am primarily authoring Maple-graded and Mathematical Formula type questions.

Can I do this in the Grading Code? Could someone illustrate this with an example? 

I'm doing this interactive component and for coordinates of points I use one TextArea for each coordinate.

a:= Do(%CB);

x1:=Do (%x1);
y1:=Do (%y1);
x2:=Do (%x2);
y2:=Do (%y2);
x3:=Do (%x3);
y3:=Do (%y3);
x4:=Do (%x4);
y4:=Do (%y4);
x5:=Do (%x5);
y5:=Do (%y5);

#x6:=Do (%x6);
#y6:=Do (%y6);
#x7:=Do (%x7);
#y7:=Do (%y7);
#x8:=Do (%x8);
#y8:=Do (%y8);
#x9:=Do (%x9);
#y9:=Do (%y9);
#x10:=Do (%x10);
#y10:=Do (%y10);




vx2:=[x1,x2];
vy2:=[y1,y2];

vx3:=[x1,x2,x3];
vy3:=[y1,y2,y3];

vx4:=[x1,x2,x3,x4];
vy4:=[y1,y2,y3,y4];

vx5:=[x1,x2,x3,x4,x5];
vy5:=[y1,y2,y3,y4,y5];



if a=2 then F2:=y=LinearFit([1, x], vx2, vy2, x);
end if:

if a=3 then F3:=evalf[2](LinearFit([1, x], vx3, vy3, x));
end if:


if a=4 then F4:=LinearFit([1, x], vx4, vy4, x);
end if:


if a=5 then F5:=LinearFit([1, x], vx5, vy5, x);
end if:

I was browsing on maple and i sow this:

I would use a table to insert coordinates of point like this image, but i don't know how can I do.

Can you help me plese?

Thanks in advance
Enrico

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