Hello, sorry for may asking the most simple question ever, but we cant find a solution.

If we do have a simple eqation like this:

U=I*R

how to solve vor R=? using maple?

Okay, we do feel really stupid for asking that and okay we can do that by hand but how to use maple for this, especially when it becomes more complex? Are there any examples of this kind?

Tahnks a lot Eve and Andrew

So if I have a procedure like 

with(GraphTheory)

tneighbors := proc (G::Graph)

local numvertices::integer, i::integer, currentvertex;

numvertices := nops(Vertices(G));

for i to numvertices do

currentvertex := Vertices(G)[i];

if nops(Neighbors(G, currentvertex)) = 2 then print(currentvertex)

end if;

end do;

end proc;

How do I make it so the output gets returned as a set?

For example, if I do  twoneighbors(G); and get
1

7

4

How do I make it so the output is listed as a set like {1,4,7}? Thanks.

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 );

Hi Maple friends.

How can I find the domain of y=sqrt(3*x-5)? or of y=1/(x+2)^2?

Thanks in advance.

Hi everyone!

I wander whether maple can solve the integral of trigonometric series with parametal N, the number of sereis, and how. The formation is showed as below. N is a  variable and 'm' belongs to 'k', 'n' belongs to 'l'.

A := int(int(sum(sum(cos(2*k*Pi*x/a)*(1-cos(2*l*Pi*y/b))*(1-cos(2*m*Pi*x/a))*(1-cos(2*n*Pi*y/b)), k = 1 ..N), l = 1 .. N), x = 0 .. a), y = 0 .. b)

orthogonality codition 1:

OrthCondition1 := int(sum(cos(2*k*Pi*x/a)*cos(2*m*Pi*x/a), k = 1 .. N), x = 0 .. a) = (1/2)*a

orthogonality codition 2:

OrthCondition2 := int(sum(cos(2*l*Pi*x/b)*cos(2*m*Pi*x/b), l = 1 .. N), x = 0 .. b) = (1/2)*b;

I need to write a procedure that returns the cut vertices of a graph, but I think I'm having trouble defining my local variables. This is what I have so far.  I think my error might be in defining H since that's the line the error message I get keeps referencing.  Am I defining H incorrectly or in the wrong spot? Any advice would be appreciated. Thanks

cutvertices := proc (G)

local numvertices::integer, currentvertex, i::integer, H;

description "Returns a set of all the cut-vertices of the given graph";

numvertices := nops(Vertices(G));

for i to numvertices do

currentvertex := Vertices(G)[i]

H:=DeleteVertex(G, currentvertex)

if nops(ConnectedComponents(G)) = nops(ConnectedComponents(H)) then print(currentvertex)

end if;

end do;

end proc:

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.

i want to solve an equation by fsolve but i cant assign a value as an input for next step!

please help me

s := fsolve(G), x = -1 .. 1     

s := .1449607418, x = -1 .. 1  

 a:=s+1  

Error, invalid input: subs received .1449607418, which is not valid for its 1st argument                  

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.

See AAAA.mw

The alpha and beta are 'randomly' chosen, both >0, to produce some values, hence a value for the target function to optimize.

I am having trouble to evaluate the expression in the middle of the calculation.

Sometimes, the 'chosen' alpha and beta works fine with 'method = _d01amc' for numerical integration. and such way is really "fast".

But sometimes, the the 'chosen' alpha and beta will fail. Even when both of them are perfectly defined. and the integral can be easily evaluated using Int() and then evalf().

So what's be best way to proceed?

Thanks,

casperyc

Consider the following sum:


We know that if k is between 1 and N, the result will be



and otherwise the sum is zero.

How can I tell maple to compute this sum in each case without giving numerical values to the parameters "N" and "k"?

Thanks. :)