A=zeros(12,1);n=3;m=4;for i=1:n for j=1:m if i==1 && j==m A(1,1)=1; elseif (i==1) && (j>1 || j<m) A(2,1)=2; elseif (i==1) && (j==m) A(3,1)=3; endAMATLAB: Why elseif (i==1) && j==m condition went unexecuted
elseif
Related Solutions
You want the third condition to execute the i==1 and j==4. However, this also meets the conditions of the first elseif:
elseif (i==1) && (j>1 || j<m)
This is because you use "or" instead of "and". When j==4, it is >1. Because of the or, it doesn't matter that it is <m. Try this instead: elseif (i==1) && (j>1 && j<m)
Lots wrong with that code. Gladd to see that you're using a failsafe (limit to number of iterations though). Here, just try this. I fixed several things.
FL=0.04; %Fin length
BL=0.005; %Base length
TL=BL+FL; %Total length
FW=0.010; %Fin width
BW=0.030; %Base width
dx=0.001;dy=dx;%Total Nodes
M=round(((BW/2)/dx+1)); % i Direction
N=round(((TL)/dx+1)); % j Direction
%Initial Temperature
T=zeros(M,N);maxLoopIterations = 10000; % Number of Iterations
err_max = 1e-6; % Maximum Error
n=0; %Number of Iterations
err = zeros(1, maxLoopIterations);while n < maxLoopIterations n=n+1; Tp=T; for i=1:1:M for j=1:1:N %Corner Node 8
if i==1 && j==1 %(i=0, j=0)
T(i,j)=(1/2)*(T(i,j+1)+T(i+1,j))+(7500/89)*dx; %Corner Node 13
elseif i==M && j==1 %(i=15, j=0)
T(i,j)=(1/2)*(T(i,j+1)+T(i-1,j))+(7500/89)*dx; %Corner Node 9
elseif i==1 && j==N %(i=0, j=45)
T(i,j)= (89*(T(i+1,j)+T(i,j-1))+4500*dx)/(150*dx+178); %Constant heat flux boundary node 5
elseif i>1 && i<M && j==1 %(i=1 to 14, j=0)
T(i,j)=(1/4)*(T(i-1,j)+T(i+1,j))+(1/2)*(T(i,j+1))+(7500/89)*dx; %Symmetrical boundary node 2
elseif i==1 && j>1 && j<N %(i=1 , j=1 to 45)
T(i,j)=(1/4)*(T(i,j+1)+T(i,j-1))+(1/2)*(T(i+1,j)); %Convective boundary node 7
elseif i>1 && i<6 && j==N %(i=1 to 4 , j= 45)
T(i,j)=((89)*(T(i-1,j)+T(i+1,j))+(178)*(T(i,j-1))+9000*dx)/(300*dx+356); %Convective Corner Node 10
elseif i==6 && j==N %(i=5 , j= 45)
T(i,j)=((89)*(T(i-1,j)+T(i,j-1))+9000*dx)/(300*dx+178); %Convective Boundary Node 3
elseif i==6 && j>5 && j<N %(i=5, j= 5 to 44)
T(i,j)=((89)*(T(i,j+1)+T(i,j-1))+178*T(i-1,j)+9000*dx)/(9000*dy+356); %Corner Node 11
elseif i==6 && j==6 %(i=5, j=5)
T(i,j)=((178)*(T(i-1,j)+T(i,j-1)+T(i+1,j)+T(i,j+1))+4500*dy)/(150*dy+534); %Corner Node 12
elseif i==M && j==6 %(i=15, j=5)
T(i,j)=((89)*(T(i-1,j)+T(i,j-1))+4500*dx)/(150*dx+178); %Convective Boundary Node 6
elseif i>5 && i<M && j==6 %(i=5 to 15, j=5)
T(i,j)=((178)*(T(i,j-1))+(89)*(T(i+1,j)+T(i-1,j))+9000*dx)/(9000*dx+356); %Symmetrical Boundary Node 4
elseif i==M && j>1 &&j<6 %(i=15, j=1 to 4)
T(i,j)=(1/4)*(T(i,j-1)+T(i,j+1))+(1/2)*(T(i-1,j)); %Internal Node 1 (SOLID)
elseif i>1 && i<M && j>1 && j<6 T(i,j)=(1/4)*(T(i,j-1)+T(i,j+1)+T(i+1,j)+T(i-1,j)); %Internal Node 1 (SOLID) elseif i>1 && i<6 && j>5 && j<N T(i,j)=(1/4)*(T(i,j-1)+T(i,j+1)+T(i+1,j)+T(i-1,j)); end end end diffMatrix = abs(T - Tp); err(n) = max(diffMatrix(:)); if err(n) < err_max break endend% Crop off unused part of array
err = err(1:n);plot(err, 'b-', 'LineWidth', 2);grid on;drawnow;fontSize = 20;title('Error vs. Iteration Number', 'FontSize', fontSize);xlabel('Iteration Number', 'FontSize', fontSize);ylabel('Error', 'FontSize', fontSize);xticks(0:100:n);yticks(0:.01:.15);
Best Answer