How to change initial condition?
3 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
ffunction [u,x,t] = wave(a,xf,T,it0,i1t0,bx0,bxf,M,N)
%solve a u_xx = u_tt for 0<=x<=xf, 0<=t<=T
% Initial Condition: u(x,0) = it0(x), u_t(x,0) = i1t0(x)
% Boundary Condition: u(0,t)= bx0(t), u(xf,t) = bxf(t)
% M = # of subintervals along x axis
% N = # of subintervals along t axis
%solve_wave
a = 1;
it0 = inline('x.*(1-x)','x'); i1t0 = inline('0'); %initial condition
bx0 = inline('0'); bxf = inline('0'); %boundary condition
xf = 1; M = 10; T = 2; N = 10;
dx = xf/M; x = [0:M]'*dx; %space step size
dt = T/N; t = [0:N]*dt; %time step size
for i = 1:M + 1, u(i,1) = it0(x(i));
end
for k = 1:N + 1
u([1 M + 1],k) = [bx0(t(k)); bxf(t(k))];
end
r = a*(dt/dx)^ 2; r1 = r/2; r2 = 2*(1 - r);
u(2:M,2) = r1*u(1:M - 1,1) + (1 - r)*u(2:M,1) + r1*u(3:M + 1,1) ...
+ dt*i1t0(x(2:M));
for k = 3:N + 1
u(2:M,k) = r*u(1:M - 1,k - 1) + r2*u(2:M,k-1) + r*u(3:M + 1,k - 1)...
- u(2:M,k - 2);
end
figure(1), clf
mesh(t,x,u)
figure(2), clf
for n = 1:N %dynamic picture
plot(x,u(:,n)), axis([0 xf -0.3 0.3]), pause(0.2)
end
How to change my initial equation to this? u(x,0)=f(x) where

0 commentaires
Réponses (0)
Voir également
Catégories
En savoir plus sur Assembly dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!