Hi,

While using pdsolve for a coupled system of pdes, the maple results doen't match with the desired ones.

Here is the system

restart:

Eq1:=diff(f(eta,tau),eta$3)+(f(eta,tau)+h(eta,tau))*diff(f(eta,tau),eta$2)-diff(f(eta,tau),eta$1)^2

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

Eq2:=diff(h(eta,tau),eta$3)+(f(eta,tau)+h(eta,tau))*diff(h(eta,tau),eta$2)-diff(h(eta,tau),eta$1)^2

+c*(1+epsilon*cos(Pi*tau...

ASK.zip

Hi all,

In short, I want to use

'ss' expression(1)

to simplify

'kappa' expression (2).

At the moment, I can only archieve it through solving for each variable and get to expression (5).

 

simplify using siderules failes in this case. Is there another way to do it?

 

Thanks,

 

Casper

Hi, 

Struggling to get my head round how to plot the results of the follwoing, as it seems I have 4 variables...

I have a data file containing the results of the following problem:

1) Consider a cube. Each side (a,b,c) has a length of 1 unit.

2) Place an ion (0,0,0) where [a,b and c intersect] and find the associated energy at that point.

3) Move the ion to a point 0.05 units along side a to (0.05,0,0) and re-find the associated energy.

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);

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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 ,