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Hi all,

I need to solve det[M]=0 for omega.

M is:

M := Matrix(8, 8, {(1, 1) = BesselJ(n, tp*a), (1, 2) = 0, (1, 3) = 0, (1, 4) = 0, (1, 5) = -BesselJ(n, tg*a), (1, 6) = -BesselY(n, tg*a), (1, 7) = 0, (1, 8) = 0, (2, 1) = k*n*BesselJ(n, tp*a)/(tp^2*a), (2, 2) = I*k*n*mu0*omega*(diff(BesselJ(n, tp*a), a))/(tp^2*a), (2, 3) = 0, (2, 4) = 0, (2, 5) = -k*n*BesselJ(n, tg*a)/(tg^2*a), (2, 6) = -k*n*BesselY(n, tg*a)/(tg^2*a), (2, 7) = -I*`μg`*omega*(diff(BesselJ(n, tg*a), a))/tg^2, (2, 8) = -I*`μg`*omega*(diff(BesselY(n, tg*a), a))/tg^2, (3, 1) = 0, (3, 2) = BesselJ(n, tp*a), (3, 3) = 0, (3, 4) = 0, (3, 5) = 0, (3, 6) = 0, (3, 7) = -BesselJ(n, tg*a), (3, 8) = -BesselY(n, tg*a), (4, 1) = -I*omega*`ϵp`*(diff(BesselJ(n, tp*a), a))/tp^2, (4, 2) = k*n*BesselJ(n, tp*a)/(tp^2*a), (4, 3) = 0, (4, 4) = 0, (4, 5) = I*`ϵg`*omega*(diff(BesselJ(n, tg*a), a))/tg^2, (4, 6) = I*`ϵg`*omega*(diff(BesselY(n, tg*a), a))/tg^2, (4, 7) = -k*n*BesselJ(n, tg*a)/(tg^2*a), (4, 8) = -k*n*BesselY(n, tg*a)/(tg^2*a), (5, 1) = 0, (5, 2) = 0, (5, 3) = k*n*BesselY(n, t0*b)/(t0^2*b), (5, 4) = I*mu0*omega*(diff(BesselY(n, t0*b), b))/t0^2, (5, 5) = -k*n*BesselJ(n, tg*b)/(tg^2*b), (5, 6) = -k*n*BesselY(n, tg*b)/(tg^2*b), (5, 7) = -I*`μg`*omega*(diff(BesselJ(n, tg*b), b))/tg^2, (5, 8) = -I*`μg`*omega*(diff(BesselY(n, tg*b), b))/tg^2, (6, 1) = 0, (6, 2) = 0, (6, 3) = BesselY(n, t0*b), (6, 4) = 0, (6, 5) = -BesselJ(n, tg*b), (6, 6) = -BesselY(n, tg*b), (6, 7) = 0, (6, 8) = 0, (7, 1) = 0, (7, 2) = 0, (7, 3) = 0, (7, 4) = BesselY(n, t0*b), (7, 5) = 0, (7, 6) = 0, (7, 7) = -BesselJ(n, tg*b), (7, 8) = -BesselY(n, tg*b), (8, 1) = 0, (8, 2) = 0, (8, 3) = -I*epsilon0*omega*(diff(BesselY(n, t0*b), b))/t0^2, (8, 4) = -k*n*BesselY(n, t0*b)/(t0^2*b), (8, 5) = I*`ϵg`*omega*(diff(BesselJ(n, tg*b), b))/tg^2, (8, 6) = I*`ϵg`*omega*(diff(BesselY(n, tg*b), b))/tg^2, (8, 7) = -k*n*BesselJ(n, tg*b)/(tg^2*b), (8, 8) = -k*n*BesselY(n, tg*b)/(tg^2*b)});

and n=0,1,2.

Except of omega and k ,other parameters is canstant.

After using
detM := Determinant(M):

I used solve(detM=0,omega) and fsolve() but it dosnt work. how can i solve it?

Thanks alot.

Hi fellow Maple users,

I'm trying to solve an eigenvalue problem of Ax=wx, where A is a 6 by 6 Hermitian matrix with two parameters x and y. I want to solve it for w and then plot3d it with x and y as unknowns. The way I have been doing is first find the characteristic equation Determinant(A-wI)=0 and then solve it for w, and then plot3d the solutions within a range for x and y. My problem is sometimes solve(Determinant(A-wI)=0,w) would give me the 6 solutions expressed in x and y, but sometimes when the numbers in A are changed it will only give me a Rootof solution with which I cannot plot. I'm wondering if there is a better way to do this. I'm actually not very interested in the symbolic solution of w expressed in x and y, just the plot, so if there is a numerical alternative it's good too.

Thank you in advance!

Hello Everyone


I am new to Maple and I have to find the determinant of the following matrix


Matrix comprising of Bessel Functions whose determinant is to be calculated

Here k is a constant.


Can you please help me with it.


Thanks in advance.

Hi there,


I am trying to compute the following, and I am getting this error.


> A := map(convert, M, unit_free)*Unit('m'*(1/'s'^2));
(I had to put the Unit('m'*(1/'s'^2)) because the original units were kNm/s^2 (kg), and even though I simplified it, it's still using kNm/s^2, and leaves the m/s^2 for some reason when I try to remove the units. I tried simply changing the units on the original matrix, but the units menu has disappeared from the right-click menu!!)

> B := map(convert, K, unit_free);


Loading RealDomain;


Error, (in assuming) when calling 'Engine:-Dispatch'. Received: 'should not happen: Rename expects the input to contain unknown functions'

Why is it giving me this error? omega is an unknown variable that I am trying to solve for. I am going a modal analysis, so maybe there is a better way to find omega?


Any help appreciated!




Recently a a simple problem which i can not handle by myself, made me confused.

I have simple code of maple which is not stable at all. Everytime I run the code, the final result which is the determinant of a matrix, changes and I can not see the problem with the code. In fact i noticed that problem occures when the matrix is being build by culculating the coefficients of some constant values.  I have attached the code. Could you see what is wrong here?

Thanks by the way.



Determine using determinants the range of values of a (if any) such that
has a minimum at (0,0,0).

From the theory, I understand that if the matrix corresponding to the coefficients of the function is positive definite, the function has a local min at the point. But, how do I get the range of values of a such that f is a min? Is this equivalent to finding a such that det(A) > 0?



Now modify the function to also involve a parameter b: g(x,y,z)=bx^2+2axy+by^2+4xz-2a^2yz+2bz^2. We determine conditions on a and b such that g has a minimum at (0,0,0).
By plotting each determinant (using implicitplot perhaps, we can identify the region in the (a,b) plane where g has a local minimum.

Which region corresponds to a local minimum?

Now determine region(s) in the (a,b) plane where g has a local maximum.

I don't understand this part at all..



I want to compute the determinant of a matrix A with this formula:

 Can someone help me to do it.  Of course, here I am using Einstein's convention.

Thank you in advance.

Mario Lemelin
Maple 18 Ubuntu 14.04 LTS - 64 bits
Maple 18 Win 7 Pro - 64 bits messagerie : téléphone :  (819) 376-0987

I have following expression


which is 1 solution of the ODE

ode2 := -(diff(y(t), t, t))+(4-12/(1+s*cosh(2*t))+(8*(-s^2+1))/(1+s*cosh(2*t))^2)*y(t) = 0

Now I wanted to construct 2 linear independent solutions via:



and calculate the Wronskian:

with(LinearAlgebra); with(VectorCalculus)

Determinant(Wronskian([f(t_b-t), f(t-t_a)], t))

Since I know these functions are solutions of the second order ODE which does not contain any first order derivative the Wronskian should be a constant. Unfortunately Maple has a hard time to simplify it since the epxression is a little big. Is it my fault or has anyone an idea what to do?

Dear users,

I have a Maple file to evaluate the shape functions on hexahedrons and to save the results in a .cpp file. However, the execution time is very long and when I do not loose the connection with the server, I ran out of memory (I have 32GB!!). So, I very keen to hear some tips on how to optimize it! I am sure this computation is simple enough for the Maple powerful and I quite sure there are some tricks to optimize it! The code is below.

Thanks in advance!

I have a matrix of order 14 with whose entries being variables about u_1 to u_12. I want to get its determinant, but it return no results. It explains that it is too big for maple to deal with. So I wonder how to deal with such kind of this problem?

Thank you very much for kind attention!


I have the following problem:

My function is defined by the determinant of 2 Heun functions

If I plot the phase I get something which looks quite what I'm looking for.

To get a better result I thought I would manually carry out the Wronskian as far as possible...

Doing some manipulations I get another form of the Wronskian which in fact should give the same result...

the problem is it doesnt :-(

I've added the spreadsheet....

Hello everyone, new member here. I've been working with Maple 16/Mathematica 8/Matlab to find the determinants of some symbolic nxn matrices (a1,1 a1,2 etc). Matlab is able to do them quite easily but when they start getting too large it starts truncating them down to 25000 terms. Mathematica works like a charm but I want to beable to verify the results with Maple. Maple does great up to 7x7  but at 8x8 it seems to also truncate results like Matlab and past that...

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