Hello!

I want to use abstract linear operators between Lie algebras. I have the problem shown in the following short code:

with(LinearAlgebra): with(DifferentialGeometry): with(LieAlgebras):
LAr:=LieAlgebraData([ [e1,e2]=e3],[e1,e2,e3],LA);
DGsetup(LAr);
define(lin,linear);
lin(-e3);
lin(-LieBracket(e1,e2));
lin(LieBracket(e2,e1));

As you see, the minus "-" does not come out of the argument of lin() in the last line. What is going wrong?

Thanks!

-------------------------------------

Later on, I realized that the linear operator has nothing to do with the issue. The problem lies in the fact that the output of "LieBracket(e2,e1)" is "_DG([["vector", LA, []], [[[3], -1]]])" , where the latter "-1" refers to the coeffiecient. For some reason, this coefficient is not handled in the way I would expect. For example, the following two lines:

LieBracket(e2,e1)+LieBracket(e1,e2);
_DG([["vector", LA, []], [[[3], 1]]])+_DG([["vector", LA, []], [[[3], -1]]]);

give both as an output "e3+-e3" instead of "0", while both the lines

LieBracket(e2,e1) + LieBracket(e2,e1);
_DG([["vector", LA, []], [[[3], -1]]])+_DG([["vector", LA, []], [[[3], -1]]]);

give the output "2-e3" (which I interpret as "2(-e3)" ).

I don't understand what I am doing wrong.

I have PDE i trying to solve the equation using series.

pdsolve(diff(u(x, y), x, x)+diff(u(x, y), y, y) = Pi, series, order = 2);

Give me: "Error, (in DifferentialAlgebra:-RosenfeldGroebner) unexpected occurrence of the non-rational constants {Pi} in the given input" ?

pdsolve(diff(u(x, y), x, x)+diff(u(x, y), y, y) =gamma, series, order = 2);#gamma = 0.5772156649,Gives ERROR ?

If I  change instead of Pi is e or exp(1) works fine.

pdsolve(diff(u(x, y), x, x)+diff(u(x, y), y, y) = exp(1), series, order = 2);#OK.

It's a bug, design or  something else ?

Goodday sirs, 

            How can I get over these error message123.mw
 

Anyone with useful informations please.

Thanking you in anticipation for a favurabke response

Download 123.mw

pde := [diff(u(x, y), x, x)+diff(u(x, y), y, y) = 2*Pi*(2*Pi*y^2-2*Pi*y-1)*exp(Pi*y*(1-y))*sin(Pi*x), u(0, y) = sin(Pi*y), u(1, y) = exp(Pi)*sin(Pi*y), u(x, 2) = exp(-2*Pi)*sin(Pi*x), u(x, 0) = u(x, 1)]pdsolve(pde)

pdsolve(pde)

it does not return any solution and answer, kindly help.

Hi, 

I have a vector field that has positive constants. I don't want to set perminant values for the constants becuase future calculations will be wrong. 

Instead, how can I set a sample set of values for these constants? Thanks

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Can't seem to get Retrieve from DocumentTools to get any labels from any worksheet.  I just get an error saying unable to retrieve label reference.

with(DocumentTools):

Retrieve("c:/test/test/mw","L1") #sample test file named test.mw in directory test

Here's the same issue (unanswered) way back in 2015 https://www.mapleprimes.com/questions/203811-DocumentTools-Retrieve-Function-Returns

Maybe it's a Windows administrator issue?  Does it work for anyone else?

restart;

u1 := proc (x, y) options operator, arrow; 1-e^(a*x)*cos(2*Pi*y) end proc;
a := -.39323780;
evalf(int(int(u1(x, y)^2, y = -.5 .. 1.5), x = -.5 .. 1.5));
             1             /                  /          5 
  ------------------------ \0.000002034392421 \6.25000 10  
         (5898567/5000000)                                 
  ln(e) e                                                  

     (1966189/1250000)              6        (5898567/5000000)
    e                  + 1.966189 10  ln(e) e                 

                 5\\
     - 6.25000 10 //

I need help me , how can find this integral as simple number?

u1 := proc (x, y) options operator, arrow; 1-e^(a*x)*cos(2*`πy`) end proc;
u2 := proc (x, y) options operator, arrow; a*e^(a*x)*cos2*`πy` end proc;

norm(u2(x, y), 2)/norm(u1(x, y), 2);
Error, invalid input: norm expects its 1st argument, p, to be of type {Matrix, Vector, matrix, polynom, vector}, but received a*e^(a*x)*cos2*`πy`

Hi, I want to define A matrix (shown below) that has some definite products. These products have two arguments e.g. (k=1..N) and (k<>i) but product expects only one argument. What should I do?

I appreciate any help you can provide.

Hi,

How to import and manipulate different formulas of  Excel files in maple ?

See example in attachment

Thanks

Hi all

I wnat to produce following matrix P_{2r+1, 2r+1} in maple.

can any one help me please?

Error, (in dsolve/numeric/process_input) system must be entered as a set/list of expressions/equations
moadele_asli2.mw

solve does not show result!!

dtm.mw