Conversion to double from function_handle is not possible error message
2 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
I'm trying to approximate the 1D diffusion equation and when i try to run the function I get the error message "Conversion to double from function_handle is not possible error message." Here is the function:
function [u]=fixeddiffusion(h,N,dt,t0,theta,u0,uN,uinitial,x0,xN,uexact)
x=zeros(N+1,1);
x(1)=x0;
x(N+1)=xN;
uvec=zeros(N+1,1);
uvec(1)=u0;
uvec(N+1)=uN;
A=zeros(N-1,N-1);
a=-2/(h^2);
for i=1:N-1
A(i,i)=a;
end
b=(1/(h^2));
for i=1:N-2
j=i+1;
A(i,j)=b;
end
for i=2:N-1
k=i-1;
A(i,k)=b;
end
b=zeros(N-1,1);
for i=1:N-1
b(i)=uinitial(i+1);
end
uu=A\b;
for i=1:N-1
uu(i)=uvec(i+1);
end
u=zeros(N+1,1);
u(1)=u0;
for i=2:N
u(i)=u(i-1)+dt*((1-theta)*uvec(i-1)+theta*uvec(i));
end
t=zeros(N+1);
for i=1:N+1
t(i)=t0+(i-1)*dt;
end
ureal=zeros(N+1,1);
for i=1:N+1
ureal(i)=uexact(x(i),t(i));
end
figure(1)
plot(t,u,'.',t,ureal,'--');
legend('Approx:','True:');
error=zeros(N+1,1);
error=abs(u-ureal);
norm=zeros(N+1,1);
norm(i)=symsum((h*dt(abs(error(i)^2)))^(1/2),error(i),1,i);
end
Here is the script i'm trying to use.
uinitial=@(x,t)sin(pi*x);
u0=0;
uN=0;
h=0.1;
N=1/0.1;
dt=0.0005;
theta=0;
x0=0;
xN=1;
uexact=@(x,t)exp((-pi^2)*t)*sin(pi*x);
[u]=fixeddiffusion(h,N,dt,theta,u0,uN,uinitial,x0,xN,uexact)
0 commentaires
Réponses (1)
dpb
le 10 Mar 2020
function [u]=fixeddiffusion(h,N,dt,t0,theta,u0,uN,uinitial,x0,xN,uexact)
...
b=zeros(N-1,1);
for i=1:N-1
b(i)=uinitial(i+1);
end
...
end
but
uinitial=@(x,t)sin(pi*x);
...
[u]=fixeddiffusion(h,N,dt,theta,u0,uN,uinitial,x0,xN,uexact)
passes a function handle for uinitial that is treateda as an array in the function.
Voir également
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!