clear clc
dx=0.5
nx=uint32(5/dx+1)
ny=uint32(5/dx+1)
[X Y]=meshgrid(linspace(0,5,nx),linspace(0,5,ny))
Tint=0
T=Tint*ones(ny,nx)
Tleft=100
Tright=0
Ttop=0
Tbottom=0
T(:,1)=Tleft
T(:,end)=Tright
T(1,:)=Ttop
T(end,:)= Tbottom
k=3
itr=200
for k=1:itr
for i=2:nx-1
for j=2:ny-1
T(j,i)=((T(j-1,i)+T(j+1,i)+T(j,i-1)+T(j,i+1))/4)
end
end
end
[Xq Yq]= meshgrid(linspace(0,5,nx*10),linspace(0,5,ny*10));
colormap jet
Vq=interp2(X,Y,T,Xq,Yq,'cubic',0);