Real application running a very long time in elimination step

z1 := Diff(x1(t),t) = x2(t);

z2 := Diff(x2(t),t) = x3(t);

z3 := Diff(x3(t),t) = x4(t);

z4 := Diff(x4(t),t) = -1*(1.0000*x4(t)-.5109*x3(t)-0.595e-1*x2(t)+3.1086*10^(-15)*(Diff(u(t), t, t, t))-(Diff(u(t), t, t))+.5109*(Diff(u(t), t))+0.595e-1*u(t));

with(Involutive):

with(OreModules):

Alg := DefineOreAlgebra(diff=[D,t], polynom=[t], comm=[a1,a2,a3,u]):

DD := evalm([[D, -1, 0, 0, 0],[0, D, -1, 0, 0],[0, 0, D, -1, 0],[0, -0.0595, -0.5109, D+1, (3.1086*10^(-15))*D^3-D^2+0.5109*D+0.0595]]);

DDtilde := Involution(DD,Alg);

ApplyMatrix(DDtilde, [lambda1(t),lambda2(t),lambda3(t),lambda4(t)],Alg)=evalm([[miu1(t)],[miu2(t)],[miu3(t)],[miu4(t)],[miu(t)]]);

E := Elimination(DDtilde, [lambda1,lambda2,lambda3,lambda4],[miu1,miu2,miu3,miu4,miu],Alg);

Reply With Quote

The goal is to get Kalman Form

https://docs.google.com/file/d/0Bxs_ao6uuBDUT25BeVhtWjZwRUU/edit?usp=sharing

https://docs.google.com/file/d/0Bxs_ao6uuBDUVXU5dXh6Rl9zUUU/edit?usp=sharing

 

I am doing the example in page 707 of Partial Differential control theory Volume 2 by J.F.

 

when using Robertz Daniel's Ore and Involutive packages

 

with(Involutive):

with(OreModules):

Alg := DefineOreAlgebra(diff=[D,t...

Find a(n)of sequence:5, 7, 7, 2, 1, 5, 6, 6, 4, ...............

Hello everyone,

I have a system of PDEs

restart:with(PDEtools):with(plots,implicitplot):

Pr:=1:A:=1:lambda:=1:Omega:=1:epsilon:=1:C1:=1:N:=5:b:=1:fw:=1:a:=1:

Eq1:=diff(f(eta,tau),eta,eta,eta)-diff(theta(eta,tau),eta)*diff(f(eta,tau),eta,eta)+

f(eta,tau)*diff(f(eta,tau),eta,eta)-(diff(f(eta,tau),eta))^2-(1+A*(1-theta(eta,tau)))*diff(f(eta,tau),eta)

+lambda*(1+epsilon*cos(Pi*tau))*theta(eta,tau)-Omega*diff(diff(f(eta,tau),tau),eta);

Hello everyone,

I am dealing with an Eigen value problem, the equations are

restart:with(plots):

Eq1:=diff(f(y),y$2)-a^2*f(y)+a*(h(y)+R*q(y))=0;

Eq2:=diff(h(y),y$2)-a^2*h(y)+a*Z*y*f(y)=0;

Eq3:=diff(q(y),y$2)-a^2*q(y)+a*f(y)=0;

ic:=f(0)=0,f(1)=0,D(h)(0)=0,q(0)=0,h(1)=0,q(1)=0;

where f,h,q are Eigen functions, R, Z are dimensionless...

 

I am using Maple 13, I am working on Optimtimization package (worksheet mode) in command-line 

I have equations in microsoft word file and I have to copy the...

Hello everyone,

I saw a question on a different forum related to the stability of the numerical solution of a coupled ode system. The original question was about the convergence of the far field condition (infinity) for some specific values of the different parameters involved.  For the details please see the link below

http://mathematica...

Hi,I want to compute some expressions as binomial(d-2,r)*binomial(v-d-1,r-1) and something like that. In the process, there are many such expressions but with differernt parameters. Some of them can pass successfully, but some of them will generate a mistake. That is: Error, (in gcd/LinZip) variable in input expression must be in either the evaluate or retained variables.Could you please what happened to it? Thanks.

Hello

 I wish to solve nonlinear PDE equation numerically  in u & v coordinate . where u=t-x, v=t+x . we note x=(v-u)/2.. 

pde := diff(u(t,x),t,t) - diff(u(t,x),x,x) + x^2*u(t,x);  

 

 We need only initial condition let f(u)=sech(u) & g(v)=sech(v). So u((i,0)=f(ih), u(0,j)=g(jh) 

we summe step size of time j =  step size of spatial i .

the stencil we use , 

Bonjour,

Je cherche une méthode éfficace pour résoudre le système d'équations polynomiales suivant :

with(SolveTools):
> PolynomialSystem({f0,f1,f2,f3,f4,f5,f6},{alpha,lambda,mu,nu}); 

# avec les fi ci-dessous :

f0:= (1+mu+nu+lambda)*alpha^3*(1+mu+nu)*(mu^2-2*mu*alpha+2*nu*alpha*mu+2*mu-2*nu*alpha+2*nu*alpha^2+alpha^2-2*alpha+1+alpha^2*nu^2)*(-lambda*alpha^3+3*mu*nu+alpha^2*lambda-lambda+3*nu*mu^2+3*nu*mu^2*lambda+l...

 

I want to use Maple (dsolve command) to solve this problem, how do I input the command? Part (a) is enought.

I have tried the command, but Maple says "Warning, for {u(t)} arbitrary the system is inconsistent".

Thank you very much for your help.

Hello everyone!  

I am very new to the maplesoft community but am very impressed with everything I have learned in the last few days.  I'm having an issue using force probes on a double wishbone suspension that I'm hoping someone can help me with.  I am trying to measure the forces in each link to gather quantitative solutions for the forces at the chassis connection points.  However, I keep getting one of the links measuring no value at all.  The...