From: Ryan Cotterill on
Im using mask to set where temperatures need to go.

Basically its a rectangle box with a hole through it, the hole has a liquid of 80 degrees C going through it and the outer edges of the rectangular shape are at 20 degrees.

So I got my mask matrix to have 0's where the hole is and i need to assign the 80 degree temperature to this hole of 0's.

From what I have the mask comes out ok with 0's in the right place but after that the matrix seems to change size. Any ideas?

tedge = 20;
tcore = 80;

side = 100;
h = 2.5;
[x y] = meshgrid(-side/2:h:side/2,-side/2:h:side/2);
[M N] = size(x);
Rcore = 19.05;
mask = (x.^2 + y.^2) > Rcore^2;
%assign boundary conditions
for x = 1:41
for y = 1:41
if mask(x,y) == 0;
X(x,y)=tcore;
end
end
end