ema

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10 years, 298 days

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These are questions asked by ema

Good evening, dear experts. 

I want to solve the system of PDEs, but i get a mistake:

"Error, (in pdsolve/numeric/xprofile) unable to compute solution for t>HFloat(0.0):

solution becomes undefined, problem may be ill posed or method may be ill suited to solution"

How  can I determine the method for pdsolve?
Thanks for answers.


It's my file with the functions:
restart;
alias(X = x(t, tau), Y = y(t, tau));
xt, yt := map(diff, [X, Y], t)[];
xtau, ytau := map(diff, [X, Y], tau)[];
M := (xtau*(-Y+.1*X)+ytau*X)/(xtau^2+ytau^2);
pde1 := xt = -Y+.1*X-xtau*M;
pde2 := yt = -M*ytau+X;

cond := {x(0, tau) = 1, x(t, 0) = 1, y(0, tau) = 1, y(t, 0) = 1};
Sol := pdsolve({pde1, pde2}, cond, numeric, time = t, range = 0 .. 1);
Sol:-value(t = 1);
%;
Error, (in pdsolve/numeric/xprofile) unable to compute solution for t>HFloat(0.0):
solution becomes undefined, problem may be ill posed or method may be ill suited to solution

 

 

Hello, everyone. I'm sorry for bed view. Can i solve the system of equations in maple which above this text. I had inputted the system in Maple, but there is mistake: 

Error, (in dsolve/numeric/process_input) input system must be an ODE system, got independent variables {t, tau, Q(tau)}.

Code:

eq :=

diff(x(t), t) = -y(t)-z(t)-(diff(x(Q(tau)), tau))*((diff(x(Q(tau)), tau))*(-y(t)-z(t))+(diff(y(Q(tau)), tau))*(x(t)+a*y(t))+(diff(z(Q(tau)), tau))*(b-z(t)*(x(t)-c)))/((diff(x(Q(tau)), tau))^2+(diff(y(Q(tau)), tau))^2+(diff(z(Q(tau)), tau))^2)+eps_x*q(t),

diff(y(t), t) = x(t)+a*y(t)-(diff(y(Q(tau)), tau))*((diff(x(Q(tau)), tau))*(-y(t)-z(t))+(diff(y(Q(tau)), tau))*(x(t)+a*y(t))+(diff(z(Q(tau)), tau))*(b-z(t)*(x(t)-c)))/((diff(x(Q(tau)), tau))^2+(diff(y(Q(tau)), tau))^2+(diff(z(Q(tau)), tau))^2)+eps_y*q(t),

diff(z(t), t) = b+z(t)*(x(t)-c)-(diff(z(Q(tau)), tau))*((diff(x(Q(tau)), tau))*(-y(t)-z(t))+(diff(y(Q(tau)), tau))*(x(t)+a*y(t))+(diff(z(Q(tau)), tau))*(b-z(t)*(x(t)-c)))/((diff(x(Q(tau)), tau))^2+(diff(y(Q(tau)), tau))^2+(diff(z(Q(tau)), tau))^2)+eps_z*q(t),

diff(q(t), t) = ax*(-y(t)-z(t)-(diff(x(Q(tau)), tau))*((diff(x(Q(tau)), tau))*(-y(t)-z(t))+(diff(y(Q(tau)), tau))*(x(t)+a*y(t))+(diff(z(Q(tau)), tau))*(b-z(t)*(x(t)-c)))/((diff(x(Q(tau)), tau))^2+(diff(y(Q(tau)), tau))^2+(diff(z(Q(tau)), tau))^2))+ay*(x(t)+a*y(t)-(diff(y(Q(tau)), tau))*((diff(x(Q(tau)), tau))*(-y(t)-z(t))+(diff(y(Q(tau)), tau))*(x(t)+a*y(t))+(diff(z(Q(tau)), tau))*(b-z(t)*(x(t)-c)))/((diff(x(Q(tau)), tau))^2+(diff(y(Q(tau)), tau))^2+(diff(z(Q(tau)), tau))^2))+az*(b+z(t)*(x(t)-c)-(diff(z(Q(tau)), tau))*((diff(x(Q(tau)), tau))*(-y(t)-z(t))+(diff(y(Q(tau)), tau))*(x(t)+a*y(t))+(diff(z(Q(tau)), tau))*(b-z(t)*(x(t)-c)))/((diff(x(Q(tau)), tau))^2+(diff(y(Q(tau)), tau))^2+(diff(z(Q(tau)), tau))^2))+beta*q(t):

cond := x(0) = 0, y(0) = 0, z(0) = 1, q(0) = 0:
F := dsolve({cond, eq}, [x(t), y(t), z(t), q(t)], numeric).


What program (Maple,Matlab,mathcad...) can solve, if Maple can't.

Thank's.

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