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My query is related to Maple packages "Lie algebra" and "DifferentialGeometry", I wonder can these packages help me to check isomophism between to Lie algebras, for example, suppose I have a 4-dim Lie algebra with commutation relations:

[e2, e3] = e3, [e2, e4] = - e4, [e3, e4] = - e1 

and another 4-dim Lie algebra with commutation relations

[e2, e3] = e1, [e4, e2] = e2, [e3, e4] = - e3

Can I check for isomophism between these Lie algebras if there is any using Lie algebra package ?



How to hum program repeat several times and save what data result from each time it runs?


In an assigment I have been asked to use the Eigenvectors command to find the eigenvalues and eigenvectors of a particular matrix. 

As highlighted in the following image, my questions are:

1. What is the meaning of the suffix "+0.I"? Does it mean that there are further decimal digits which are not displayed?

2. How do the first and third eigenvalues, which are equal, result in different eigenvectors? As per my understanding, equal eigenvalues should have equal corresponding eigenvectors. Please help.

I need to plot a path with curvilinear coordinates. Knowing the curvature theta and length s of  parts that compose it, I found the equations of x and y as a function of the parameter s that goes from zero to the total length.
I make an example below:

for 0 <s <2,     x = s     and

                     y = 0 (straight line)


for 2 <s <2 + Pi,        x = 2 + 2 * sin ((s-2) / 2)      and

                              y = 2 * (1-cos ((s-2) / 2)

Now I want to find the corresponding plot of x (s), y (s) (without showing s as coordinate) but I do not know what commands I can use. Can you suggest me something? Thank you

I'm tryinv to find the contents of specific bins in a maple histogram. I don't find this elementary 'function' anywhere in the help.

How do I do it? Surely it's possible w/o taking a ruler to the screen...



When I used exportplot in Maple2015 , the GIF file made easily after Enter. But when I use Engine.evaluate in Java jOpenMaple. it works for every command but exportplot. It didn't create any GIF file. I'm working on project must be use this for create animation by Maple but now that make big trouble. Any one to help this ?

VeHinhNemXien := proc(Alpha,Vbd)
  local Y,V0,alpha,X,ball,Xmax,bgr;
  Y := unapply(V0*sin(alpha)*X/(V0*cos(alpha)) - 1/2*9.8*(X/(V0*cos(alpha)))^2,alpha,V0,X);
  ball := proc(x,y) plots[pointplot]([[x,y]],color=red,symbol=solidcircle,symbolsize=40) end proc;
  Xmax := 2*Vbd^2*sin(Alpha)*cos(Alpha)/9.8;
  bgr := plot(Y(Alpha,Vbd,X),X=0..Xmax,linestyle=[2]);
  animate(ball,[X,Y(Alpha,Vbd,X)],X=0..Xmax,scaling=constrained,labels=["Độ xa","Độ cao"],frames=60,background=bgr);
  exportplot(FileTools:-JoinPath([FileTools:-TemporaryDirectory(), "dothi.gif"]), animate(ball,[X,Y(Alpha,Vbd,X)],X=0..Xmax,scaling=constrained,labels=["Độ xa","Độ cao"],frames=60,background=bgr), gif);
end proc:

save VeHinhNemXien , "D:\\VeHinhNemXien.m";

in java file

String a[];
        a = new String[1];
        a[0] = "java";
        t = new Engine(a, new EngineCallBacksDefault(), null, null);

        t.evaluate("read \"resources/VeHinhNemXien.m\";");

        t.evaluate(....query to call VeHinhNemXien to draw plot).

I checked carefully. When call it on Maple, it created GIF, but not in java. I checked queryString carefully.

New Info. I find that when I t.evaluate(....query to call VeHinhNemXien to draw plot) . this code make java stop there. that mean no code after this line can run.


Hi, I want to ask. the maple program that i have done have something wrong somewhere.

for an example changes basis

 from e_{1}e_{1}=e_{1} , e_{1}e_{2}=e_{2} maple program reading :A1 : (1,1,1)=1,B1: (1,2,2)=1

to e_{2}e_{2}=e_{2} , e_{2}e_{1}=e_{1} maple program reading :A2: (2,2,2)=1,B2: (2,1,1)=1

these changes basis above are 2 operation, left product and right product

A1 and A2 are left product, while B1 and B2 are right product,

i need to make A1 isomorphic to A2, and B1 isomorphic to B2.

by using maple program, i should get identity in matrix form 2x2

[0 1] but i get [0         1]

[1 0],            [C_{21} 0],

For isomorphism, the determinant should not be zero

here's are my maple program:

>isom := proc (A1, A2, B1, B2, n)

local i, j, k, s, r, eqns, t, TEST, BChange, sols, m, S1, S2, C;

C := matrix(n, n);

BChange := matrix(n, n);

TEST := 0; eqns := {};

for i to n do for j to n do for m to n do

S1 := sum(A1[i, j, k]*C[k, m], k = 1 .. n); S2 := sum(C[i, r]*(sum(A2[r, s, m]*C[j, s], s = 1 .. n)), r = 1 .. n);

eqns := `union`(eqns, {S1 = S2})

end do end do end do;

for i to n do for j to n do for m to n do

S1 := sum(B1[i, j, k]*C[k, m], k = 1 .. n); S2 := sum(C[i, r]*(sum(C[j, s]*B2[r, s, m], s = 1 .. n)), r = 1 .. n);

eqns := `union`(eqns, {S1 = S2})

end do end do end do;

sols := [solve(eqns)];

t := nops(sols);

for i to t do for j to n do for k to n do

BChange[k, j] := subs(sols[i], C[k, j])

end do end do;

if simplify(linalg:-det(BChange)) <> 0 then print("BChange", BChange);

print("s1", S1); print("s2", S2); print("The det is", simplify(linalg:-det(BChange)));

TEST := 1 end if end do;

if TEST = 0 then print("These two algebras are not isomorphic")

end if end proc

input maple program:

> DENDA1 := array(sparse, 1 .. 2, 1 .. 2, 1 .. 2, [(1, 1, 1) = 1]);
> DENDB1 := array(sparse, 1 .. 2, 1 .. 2, 1 .. 2, [(1, 2, 2) = 1]);
> DENDA2 := array(sparse, 1 .. 2, 1 .. 2, 1 .. 2, [(2, 2, 2) = 1]);
> DENDB2 := array(sparse, 1 .. 2, 1 .. 2, 1 .. 2, [(2, 1, 1) = 1]);
> isom(DENDA1, DENDA2, DENDB1, DENDB2, 2);

Hi All, 

I'm using the Physics package, which enables GR calculations, ie defining metrics and tensor algebra. 

Was just curious if it were possible to add a perturbation to the metric when calculating Ricci and Christoffels. 

I would like something like 

g_[] = g1_[mu,nu] + h[mu,nu] 

And then do a calculation like, 



I know this would be possible if I define everything and re-write the calculations for calculating Ricci, i.e

Define(g1[mu,nu], h[mu,nu]); 

and the proceed with GR calculations to find Ricci, however was hoping there was an easier way to do this. 

Any help is appreciated. 

Thanks guys. 

Good evening all,

How can I plot a straightline with points 

LogAt = - 0.097,  -0.20, -0.22, -0.25, -0.30 ,-0.40, -0.45, -1.01 and

t = 0, 20, 40, 60, 80, 100, 120, 140

Where LogA[t] on y-axis and t on x-axis. 

I have try this before . 

plot([[0,-0.097], [20,-0.20], [40,-0.22], [60,-0.25], [80,-0.30], [100,-0.40],  [120,-0.45],  [140,-1.01]]);

Greetings, all!

I'm extremely new to Maple T.A., and I am building tools for my math department since I'm the only one with a programming background. I have a generic question, and sincerely apologize if I've missed it being answered elsewhere. It's a case that will probably come up multiple times for us, so I was hoping to find an answer =).

I have a problem where students are adding exponents of like bases. As an example, you get questions that look like this.

When the coefficient is 1, I'd like to accept a blank answer in the first response area as a correct solution. Is there an easy (or less easy =) way of making this happen?

Thanks in advance!

I came across this interesting image restoration in the Mathematica community and wondered how this could be applied in Maple.


Hello everyone,

I have an issue that I don't know how to solve.
I would like to plot a part of a surface that is enclosed by another surface. I wrote a proc() function with an if statement and when the statement is statisfienied I returned desired function. The roblem is that if statement gets ploted as well..

Here is my proc()

yield := proc (sigma__x, sigma__y, tau__xy, sigma__cx, sigma__cy, f__45, f__cx, f__cy, tau__u, f__tx, f__ty, alpha)

if eval(evalf(f__r(sigma__x, sigma__y, tau__xy, f__tx, f__ty, alpha)) < 0) then

return f__h(sigma__x, sigma__y, tau__xy, sigma__cx, sigma__cy, f__45, f__cx, f__cy, tau__u)

else 9999999

end if

end proc;

Here is my plot request:

Explore(implicitplot3d('yield(sigma__x, sigma__y, tau__xy, sigma__cx, sigma__cy, f__45, f__cx, f__cy, tau__u, f__tx, f__ty, alpha)' = 0, sigma__x = -10 .. 10, sigma__y = -10 .. 10, tau__xy = 0 .. 10, style = surfacecontour, numpoints = 100000, axes = normal), parameters = [f__cx = 0.1e-3 .. 10, f__cy = 0.1e-3 .. 10, f__45 = 0.1e-3 .. 10, sigma__cx = 0.1e-3 .. 10, sigma__cy = 0.1e-3 .. 10, tau__u = 0.1e-3 .. 10, f__tx = 0.1e-3 .. 10, f__ty = 0.1e-3 .. 10, alpha = 0.1e-3 .. 10]

 and this is what i get:


The grainy surface should not be there. If it's not possible to remove it, it would be alright that surface would be smooth. Any ideas?

Maple evaluates:

but when I ask:

Maple will verify sin(u)/cos(u)=tan(u) but beyond that it does not seem to work too well. I suspect this has something to do with verify being a "semi-boolean" function but searching the docs for what that mean returns no results. It may mean "I am unable to decidee". But how should I know? :-(

This is Maple 2016.1 on Windows. There is a post on verifying very simple identities.

Edit As usual some very helpful answers for which many thanks. It is poor that Maple does not document the meaning of FAIL.It seems that for trig identities the expandverfier is the best.

Edit Maple documents FAIL under ? FAIL. I am not sure how I got a blank page when I searched.


Couldn't any question with title beginning with http be removed automatically? There has been quite a few containing nothing but spam.

Dear Community,

Is there an easy way to convert elapsed days since January 1 1900 to date, i.e. to year, month, day in Maple? E.g. 23021 days should convert to 1963.01.10. Also what is the opposite, i.e. from date to elapsed days?

tx in advance,

best regards


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