Hello,In short: I try to get the eigenvalues of a 16x16 complex matrix with one variable B__z. I know, the vales are very small (~10^-24), so I multiply with 10^24 and collect B__z. Now, when I use Eigenvalues(H) [H is the matrix] the result is just wrong:

test.mw

(same with original values) - compared to Mathematica which solves and plots in about 1 sec:

Where is the problem? What should I do? Any suggestions?

is it possible to assume element of matrix 0 or 1

how to write?

after write this, is it possible to display possible matrices which each element is 0 or 1

with(LinearAlgebra):
GetRing := proc(sol)
ringequation := 0;
mono1 := 0;
for j from 1 to 3 do
mono1 := 1;
for i from 1 to nops(sol[1][j]) do
mono1 := mono1*op(i, sol[1][j]);
od:
ringequation := ringequation + mono1;
od:
return ringequation;
end proc;
M := Matrix([[a1,a2,a3],[a4,a5,a6],[a7,a8,a9]]);
sys := a*b+a = GetRing(MatrixMatrixMultiply(Matrix([[a,b,c]]), M));
solve(sys);

I am running a huge symbolic problem in Maple 18. At the moment, I dont even know if there is enough computational power to suceed the computation.

However, I'd like to save a progress. And maybe to continue computation later.

Is there any way to save progress?

Hi,

I use Maple on my laptop computer (windows 8.1) with a small screen. My problem is that the text in the menus, palettes, plots etc. are so small so I can´t read it. I have set Large toolbar icons under the menu tools-options-interface and I use the zoom buttom on the toolbar but this only magnify the text in a document. I also use the magnifying glass in windows, but I find it very inflexible. Is there any better solution to this problem?

Kind Regards

Leif Jonson

I am not sure I know what is going on. I expected to obtain the controllable canonical form in this example, but I am not. May be I am not using it correctly. 

Given A,B, I wanted to transfer the state space to controllable canonical form

http://www.maplesoft.com/support/help/Maple/view.aspx?path=DynamicSystems%2FSSTransformation

In this form, the A matrix will have 1 on the super diagonal, and the last row will have the coefficients of the charaterestic polynomial in reverse order with a minus sign. The B matrix will have all zeros, except for the last entry.  This is what the example on the above page actually shows. 

But when I tried it on my A,B, I do not get this form for the new B matrix. Here is a MWE

restart;
with(DynamicSystems):
A:=Matrix([[0,0,1,0],[0,0,0,1],[-2,-1,0,0],[1,-1,0,0]]);
B:=Matrix([[0],[0],[1],[0]]);
C:=Matrix([[0,0,0,0]]):
D0:=Matrix([[0]]):
sys:=StateSpace(A,B,C,D0): #just to see the polynomial
CharacteristicPolynomial(sys, s);

SSTransformation(A,B,C,D0,form=ControlCanon,output=['A','B']);

The above should be

I am sure I am doing something wrong, but what?

Maple 18.01, windows 7

Hello,

I have a question about the CycleIndexPolynomial command contained in the Group Theory package. The answers it gives for computing the cycle index of the dihedral group and symmetric group appear to has a missing term in its answer. If my knowledge of how the cycle index is computed, it appears to be missing a term that occurs when cycles of length greater than one is combined with terms with cycles of length one. For example, here is what I get when I use Maple 18 on my Windows 8.1 machine to compute the cycle index of the following dihedral groups:

> with(GroupTheory):

> CycleIndexPolynomial(DihedralGroup(3), [x || (1 .. 3)]);

> CycleIndexPolynomial(DihedralGroup(4), [x || (1 .. 4)]);

> CycleIndexPolynomial(DihedralGroup(5), [x || (1 .. 5)]);

 Now if you compare these answers from the cycle index I found at the link:

 http://mathworld.wolfram.com/DihedralGroup.html

 you will see the answers is given as

  =

 =

 =

The disagreement occurs at the terms that contain representations of cycles of length two x2 multiplied to the one-cycle representation term x1.

The same issue happens with the symmetric group. Here is what I get for the following Maple commands:

> with(GroupTheory):

> CycleIndexPolynomial(SymmetricGroup(3), [x || (1 .. 3)]);

> CycleIndexPolynomial(SymmetricGroup(4), [x || (1 .. 4)]);

> CycleIndexPolynomial(SymmetricGroup(5), [x || (1 .. 5)]);

However, as can be seen at the link

http://mathworld.wolfram.com/SymmetricGroup.html

these answers are not in agreement with these:

  =

 =

 =

Again, the difference seems to be with terms combined with the one cycle term representation x1.

Is there something I am not interpreting correctly? Thank you for your help.

Neil Sigmon

Hi!

Do anyone know the keyboard shortcut to the standard subsribt in Maple 18 on a macbook with OS X? 

Thanks,

Mads

 in maple 12, it can not read table T in another worksheet.

i just want to read table T whenever i want during the running of big loop in procedure manman

restart;
with(Groebner):
AllMatrices := proc (A::set, k::posint, n::posint)
local B, C, E:
B := [[]]:
C := proc ()
B := [seq(seq([A[i], op(B[j])], i = 1 .. nops(A)), j = 1 .. nops(B))]:
end proc:
E := (C@@(k*n))(B):
seq(Matrix(k, n, E[m]), m = 1 .. nops(A)^(k*n));
end proc:
mm := AllMatrices({0, 1}, 3, 3);
GetRing := proc(sol)
ringequation := 0;
mono1 := 0;
for j from 1 to 3 do
mono1 := 1;
for i from 1 to nops(sol[1][j]) do
mono1 := mono1*op(i, sol[1][j]);
od:
ringequation := ringequation + mono1;
od:
return ringequation;
end proc;
with(LinearAlgebra):
polylistresult := [];
for i from 1 to nops([mm]) do
sol := MatrixMatrixMultiply(Matrix([[a,b,c]]), op(i,[mm]));
sol := GetRing(sol);
polylistresult := [op(polylistresult), sol];
od:
with(Groebner):
with(Threads):
T := Table();
m := Threads[Mutex][Create]();
manman := proc(T2, m2);
indexlistresult := [];
for i from 2 to nops(polylistresult) do
for j from 2 to nops(polylistresult) do
if i < j then
for k from 2 to nops(polylistresult) do

if j < k then
print("find");
F := [polylistresult[i], polylistresult[j], polylistresult[k]];
h := HilbertSeries(F, {x, y, z}, s);
if h <> 0 then
#if not assigned(T[h]) then
print(h);
Threads[Mutex][Lock]( m2 );
T2[h] := [op(T2[h]), F];
Threads[Mutex][Unlock]( m2 );
end if:
end if:
od:
end if:
od:
od:
end proc:
manman(T, m);
Threads[Mutex][Destroy](m);

another sheet:
Threads[Mutex][Lock]( m );
for i in indices(T) do
print(i);
od:
Threads[Mutex][Unlock]( m );

When I open my file I got an error message says "there were problems during loading process"

and some of my text are missing.

Maple Worksheet - Error

Download quant_hw_5.mwquant_hw_5.mw

Download quant_hw_5.mw

Can anyone help me,please

Hi,

I have a non linear ode with sinosoial term, (sin(x)).

How can we Analyse the system and plot the bifurcation diagram:

x'=r*x-sin(x);

Thank you very much for your help.

Hello,

One again, I have a problem to solve some bifurcation problem using maple.

Discuss the existance of Equilibria and determine any possible bifurcation.

x'=r*x-ln(x+1);

where $r$ is a parameter.

many thinks for your help and suggestion.

Hello everybody. I'm newbie and my english are not very good. Please help me debug an error in my files DSOLVE_NOT_SUCCESSFULL.zip: "Error, (in ans) cannot determine if this expression is true or false"
Thanks.

Hi

I have three system of ODE and i would like to solve it using Homotopy perturbation method. Could you please provide to me the code in Maple or the Maple pachage that used to solve it by Homotopy perturbation method ?

I hope to hear you soon

Sara

Can someone please let me know if there's a command which shows the name of the current (and running) worksheet? I would like it to be exported to an output file which is the easy part but I don't know how to automatically read it. Thank you very much.