[chberbelali]

I have just searched the Nusselt number delicate and compared it with those of other literatures,
I found that I have to do the test of stop inside the loop "While",
here is what I have added in the Matlab script:

%************************************************* *
initialize Theta;
Tnew = Theta;
Told = Tnew;

while (norm(Tnew-Told,1)/norm(Tnew),1) <= 1e-6


Told = Tnew;
.....
..... The body of the program.
.....
Tnew = Theta (Calculated);


end (while)

%*************************************************

(it doesn't work!!! it just passes the 1st iteration.)

i'll be grateful for any help !

[LuckyTran]

I would recommend testing. If you really want to test if a flag is being respected or not, try:

while false
%body of code
 end

Note that in matlab the test can be an expression and is not limited to simple logical booleans. Any non-empty vector that contains any non-zero elements will be evaluated. Also note that / is matrix division and you should be using ./ for element wise arithmetic. If you Tnew is a row vector and you do norm(Tnew,1) that will return a vector. And then if you divide a vector by a vector, unexpected things can happen.