Hi,

I tried to find the set of real parameters a1, a2, a3, a4 and u1, u2, u3 which make a subalgebra L an ideal of a finite real Lie algebra LieAlg. Unfortunately, the "Query" command with the "Ideal" argument returns an error message that I can't get around. What should I change in this command?

restart: 
with(DifferentialGeometry):
with(LieAlgebras):
#
DGsetup([x1,x2,x3],R3):
#
Lie_Generators := [D_x1*x1+D_x2*x2+D_x3*x3, D_x3*k^2*x1+D_x1*x3, -D_x1*x2+D_x2*x1, D_x3*k^2*x2+D_x2*x3, D_x1, D_x2, D_x3]:
#
LieAlg:=LieAlgebraData(Lie_Generators):
#
DGsetup(LieAlg):
#
L:= evalDG([e3+u2*e5-u1*e6,e2-u3*e5-k^2*u1*e7,e4-u3*e6-k^2*u2*e7,e1-u1*e5-u2*e6-u3*e7]);
Sub_Alg_L:=LieAlgebraData(L);
#
TrueFalse,Equations,Solutions,IdealList:=Query(L,{u1,u2,u3},"Ideal");
#
TrueFalse,Equations,Solutions,IdealList:=Query([DGzip([a1,a2,a3,a4], L, "plus")],{a1,a2,a3,a4,u1,u2,u3},"Ideal");

Thanks for your help.

Jaqr

Dear all

I would like to solve a fourth order PDEs, using fourier transform. 

How can I apply fourier transform to get solution of my problem

Fourier_transform.mw

Thank you 

Hi, 

Let's suppose 

f := piecewise(x < 1, x, -x)

Using 

discont(f, x)

says me x=1 is a discontinuity point.
But can I obtain that f is continuous over  these two intervals?

(-infinity, 1)
[1, +infinity)

Thanks in advance

PS: I'm sure I've seen this type of question here before, but I couldn't find them.

lign1 := S*`union`(T intersect R);
                 lign1 := S (`intersect`(R, T))

lign2 := (S union T) intersect (S union R);
       lign2 := `intersect`(`union`(R, S), `union`(S, T))

verify({lign1}, {lign2});

My textbook says the expression lign1 and lign2 should be the same, but it outputs false. I suspect it's because Maple is ignoring the parenthesis in the first expression.

I m Stucked with this step

Download Pblm2.mw

Hello. I want to solve a 2X2 system using Maple. I have written this code but I do not get expected results.

restart;
with(DEtools);
with(plottools);
with(plots);
with(Algebraic);

F := -1 - y - exp(x);
G := x^2 + y*(exp(x) - 1);

sol1 := eliminate({F, G}, {x, y});

sol1 := [{x = RootOf(-exp(_Z)^2 + _Z^2 + 1), y = -exp(RootOf(-exp(_Z)^2 + _Z^2 + 1)) - 1}, {}]

But, the solutions are x=0 and y=-2 (I have solved the system by hand).

Any help?!

Hi,how to separate the letters with commas, to put them in a set like { a,b,c,d} instead of {abcd} ?

Thanks

 CAP13CombinatoireQuestion.mw?

When I try to solve this problem above error displays

Here is the file
 

Download Main.mw

Hi,

When I do large computations in a worksheet and that I manually save it, I get a message in a pop-up window which asks me if I want to save these calculations too:

1. What is it that is really saved if I answer "YES" 
2. As I always answer "NO" how can I force MAPLE to ApplyGlobally this answer (I wasn't capable to fin it out in the Preferences>Interface menu).
3. is this preference accounted for during AutoSaving?

Always in the goal to save only the necessary informations (in a mw format, export to mpl format could of course be a solution), how can I remove all the outpouts (and more specifically all the plots) in the current worksheet?
Presently I'm doing this and, before my last  saving, I turn TF to false and rexecute all _display commands ... not very practical, I agree

restart

_display := proc(tf, graph)
if tf then print(graph) end if:
end proc;

TF := true: # or false if no plot is required

# for each plot:
p := display( something ):
_display(TF, p)

Thanks in advance

How to represent this function in maple?

h(x) is sin(x)/x

I use the product() but do not how to represent the step here like 1,3,5,7.... And also the integral term not working. Making Maple frozen

Thank you!

Dear all

I have two matrices represent ( f(x[i],y[j])  and  g(x[i],y[j]) of a  given two dimensional functions.

How can I use thoses values of matrices to compute the largest distance between the two curves.

Many thanks

When i try to solve the problem i got error like this 

Please help me get the solution

Download 1.mw
 

I am doing the first interactive plot in Tutorial 9:  Dynamic Applications.    The first part is Exploration Assistant.   This is mostly going OK but I don't want to have it rescale the y-axis to the data extents.   So I uncheck the box and type in my min & max values as shown below.    But when I drag the slider for coefficient a or b, the plot reverts back to using data extents.   How do I override this so that the axis range stays fixed when I drag the sliders?

I'd like to generate a string where the first part is changeable, and the second one needs to include apostrophs.

NODESteelProfiles_I:-Property("allmembers")

The section until til left bracket can be stored in one variable, but how can I add "allmembers") into the string?

Hi,

The evalDG command included in the LieAlgebras via the DifferentialGeometry package allows summations such as evalDG(e1+e2) where e1 and e2 are two generators of a given Lie algebra.

Now, let L be a list of such summations, e.g.,

L= [e1+a*e3,2*e2+b*e4,e1+3*e5]

where a and b are symbols for variable names in the real domain.
Then, while the code

evalDG(add(eval(cat(e,i)),i=1..n));

works fine (n be a given integer), the code

evalDG(add(eval(L[i]),i=1..n));

does not, and an error message results due to an "invalid subscript selector".

What is the right code to realize this summation?

Thanks.

Jaqr