help for 2D numerical sol of diffusion equation

yannoush

I am trying to write a matlab code to get the solution (steady state solution (implicit and explicit)) for the 2D diffusion equation. the fact is I am not really familiar with matlab. I think I have an equation which could be ok:

for i=2:nh-1

for j=2:nh-1

Tnew=1./(1.+(1.0-weight)*kappa*dt*4.0/(h*h))*(weight*kappa*dt/(h*h)*(T(i+1,j)+T(i-1,j)-4.0*T(i,j)+T(i,j+1)+T(i,j-1))+T(i,j)+(1.0-weight)*kappa*dt/(h*h)*(T_new(i+1,j)+T_new(i-1,j)+T_new(i,j+1)+T_new(i,j-1)));

resid=resid+abs(Tnew-T_new(i,j));

T_new(i,j)=(Tnew-T_new(i,j))*omega+T_new(i,j);

end

end

my problem is to implement the boundary conditions, the initial condition...

I hope someone can help me thank you

yann