Hi,

I am working on a instability problem where I  pose my probkem as a generalized eigenvalue problem. My matrices can reach size 3000x3000. However, even this one 

with(RandomTools); with(LinearAlgebra);
interface(rtablesize = 20);

Digits := 25;
A := RandomMatrix(200, 200);
EigVal := evalf(Eigenvalues(A));

right now running for an hour but still no result. Is there a way to speed up this process? 

Hi

i want to minimizez the "Eq1(h[1],h[2],...h[n])" for all the h[i] in the ranges of -1<h[i]<1.  "n" (number of unknown variables) can be determined during the code and was not know before. how can i do this?

It must be stated that when i have Eq1 and two unknown variables such as h[1] and h[2], i wrote the following code and it works good, but i dont know how can i write mentioned command for unknown number of variables.

NLPSolve(Eq1,h[1]=-1..1,h[2]=-1..1);

thanks for your attention in advance

I'm pleased to announce that Maplesoft is working with the team at DigiArea, Inc. to further develop and enhance their Integrated Development Environment (IDE) for Maple. When we're done, the IDE will be distributed under the Maplesoft brand, and available for purchase through our Web Store.

The IDE doesn't replace Maple's current user interface, but is instead a separate, specialized environment for developing medium- to large-scale Maple libraries. It includes tools...

my function is:

f := proc (x) if 0 < x and x < evalf(Pi) then 1 elif evalf(Pi) < x and x < evalf(2*Pi) then -1 end if end proc

now it tried:

f1 := add((-1)^n*f(x-evalf(2*n*Pi)), n = 0 .. 10)

to get a periodic function.

but unfortunately it says:

Error, (in f) cannot determine if this expression is true or false: 0 < x and x < 3.141592654

already when trying to calc the sum.

Good morning everyody,

I am trying to plot values saved in a vector but I always get the same message:
Error, (in plots:-pointplot) points cannot be converted to floating-point values
How can I fix it?

Best,

ssteve

I am trying to get Maple to solve the following rather simple non-linear system.

x=k/4, y=-k/3, z=3k/8, 2x^2+3y^2+4z^2=9

However, solve({x=k/4,y=-k/3,z=3k/8,2x^2+3y^2+4z^2=9},{x,y,z,k}) does not give the expected results. Why not?

Good afternoon everybody,

I have a problem with the evaluation of a function. You can see the test programm I have written to test the use of functions and in the end I don't get values but the expression in letters.
I think the problem lies in the definition of g but I don't know how to solve the problem.

Thank you for your help,

ssteve

Hello, 

I'd like to identify terms before the differential terms (theta(t), diff(theta(t),t) ...)

The following code with coeff function works for  diff(theta(t), t, t)) but not for diff(theta(t), t)

Here the code :

eq1pp := R(t) = -(-sin(theta[0]+phi)*Isup-sin(theta[0]+phi)*L[fixe]^2*M[fixe]-sin(theta[0]+phi)*L[r]^2*M[r]-sin(theta[0]+phi)*L[sup]^2*M[sup]+cos(theta[0]+phi)*a*sin(phi)*L[fixe]*M[fixe]+cos(theta[0...

I have just made my first polar plot, but I am a little disappointed with the result.

Code
polarplot([(1+cos(x)^2)*(1/2), cos(x)], x = 0 .. (1/2)*Pi) 

Output

How can I remove that little gap between the grey line and the black line?

Hi,

with great interest and surprise I read the post
"Converting Half-Angle Trig Formulas to Radicals".
Isnt it possible to evaluate cos(arccos(13/14)/3) also
to an exact expression in radicals ?
I simply do not succeed with my humble knowledge of
the Maple commands/internal workings...
Would be great if someone finds a solution ( of an 
unsolvable problem ??? ).

[Edit: Excess white space deleted.---Carl Love]

Good afternoon, to successfully complete my study on beam vibration i wrote a matlab code to produce all my calculations. This is the beginning of the ocde and shows the point were i get stuck:

prod2=5/2*  3200/4507*sin(pi*alp)*sin(pi*bet)/s*sin(pi*x)*pi^4*sin(pi*y)+19200/4507*sin(pi*alp)*sin(pi*bet)/s^5*sin(pi*x)*sin(pi*y)-6400/4507*sin(pi*alp)*sin(pi*bet)/s^3*sin(pi*x)*pi^2*sin(pi*y))*pi*exp(-5*(x^2-2*x*alp+alp^2-y^2+2*y*bet-bet^2)^(1/2))

heya,

i got a problem. I got a list "L" of 3d points [[x1,y1,z1],[x2,y2,z2],..[xi,yi,zi]](in maple), i can easily plot the with pointplot3d(L, axis=normal) but i would need to have them plotted in a contourplot (not the 3D one but the 2d) with contourlines at every full number (1,2,3..highest z value) (well i wont get higher z values then 20)

could you plz tell me how to do that ?

thanks michael

I am working on a program to calculate steady-state probability in a given Markov chain. My code is pasted as bellow:

CalculateSteadyStateProbability := proc (m::integer, r::integer, CV, ROU) 

local P, solutions, pai, l, eqns; 

P := CalculateMatrix(m, r, CV, ROU);    #here we calculate a (m+r)x(m+r) transition martix

eqns := {`$`('pai[i+1] = add(pai[j+1]*P[j+1, i+1], j = 0 .. m+r)', i = 0 .. m+r)

 ...

http://www.mapleprimes.com/questions/144384-Polynomials-Not-In-The-Correct-Indeterminates

above link's comment said eliminate will NOT generate a polynomial in all cases

make me think that eliminate in above link can not return correct one.

what is the correct way to convert groebner basis of kernel into kernel?

I've created som Maple-code to determine if for all entrances in a quadratic matrix, D, the inequality d_i,j <= d_{i,k +} d_k,j is true.