MATLAB: ERROR-The statement cannot be reached

statement cant be reached

theta = linspace(0,360,361); 
theta_rad = theta*pi/180; 
is_crossply = 0;
animate = 1;
an_speed = .001; 
l=[-30    4*2*.0052    1;      
60    4*2*.0052    1]; 
E = [19.4000001e6 1.4e6 .30  .702e6   -.5e-6  15e-6; 
5.84e6 .9e6  .2  .3e6    0.0e-6  0.0e-6]; 
T1_theta = @(ang) [(cos(ang))^2 (sin(ang))^2 2*sin(ang)*cos(ang); 
(sin(ang))^2 (cos(ang))^2 -2*sin(ang)*cos(ang);  
-sin(ang)*cos(ang) sin(ang)*cos(ang) (cos(ang))^2-(sin(ang))^2 ]; 
if is_crossply     
M = cosd(2*theta); 
else 
n = size(l,1); 
h = zeros(n+1,1); 
A = zeros(3); 
B = zeros(3); 
D = zeros(3);
D_0 = zeros(3); 
D_90 = zeros(3); 
D_top = zeros(3); 
D_bot = zeros(3); 
M = zeros(3,3,length(theta)); 
R = [ 1  0  0  ;       
0  1  0  ;       
0  0  2 ]; 
total = sum(l,1); 
thick = total(1,2); 
h(1) = -thick/2; 
imax = n + 1; 
for i = 2 : imax    
h(i) = h(i-1) + l(i-1,2); 
end
for j = 1:length(theta)
for i = 1:n                  
mi=l(i,3);         
v21 = E(mi,2)*E(mi,3)/E(mi,1);         
d = 1 - E(mi,3)*v21; 
 Q = [E(mi,1)/d          v21*E(mi,1)/d      0;
 E(mi,3)*E(mi,2)/d   E(mi,2)/d          0;
 0                 0               E(mi,4)]; 
 a1=l(i,1)*pi/180; 
 T1 = [(cos(a1))^2       (sin(a1))^2                2*sin(a1)*cos(a1);
(sin(a1))^2        (cos(a1))^2              -2*sin(a1)*cos(a1);
-sin(a1)*cos(a1)    sin(a1)*cos(a1)  (cos(a1))^2-(sin(a1))^2 ]; 
 Qxy = inv(T1)*Q*R*T1*inv(R); 
 A = A + Qxy*(h(i+1)-h(i));
B = B + Qxy*(h(i+1)^2 - h(i)^2);
D = D + Qxy*(h(i+1)^3 - h(i)^3); 
  if i <= n/2
disp('comp D_top')             
T1_top = T1_theta(-a1+theta_rad(j));
Q_top = inv(T1_top)*Q*R*T1_top*inv(R);
D_top = D_top + Q_top*(h(i+1)^3 - h(i)^3); 
T1_90 = T1_theta(pi/2);
Q_90 = inv(T1_90)*Q*R*T1_90*inv(R);
D_90 = D_90 + Q_90*(h(i+1)^3 - h(i)^3);
 T1_0 = T1_theta(0);
Q_0 = inv(T1_0)*Q*R*T1_0*inv(R);
D_0 = D_0 + Q_0*(h(i+1)^3 - h(i)^3);
 elseif i > n/2                       
disp('comp D_bot')             
T1_bot = T1_theta(-a1+theta_rad(j));             
Q_bot = inv(T1_bot)*Q*R*T1_bot*inv(R);             
D_bot = D_bot + Q_bot*(h(i+1)^3 - h(i)^3); 
 else             
disp('ERROR h(i)=0')         
end     
end
format short e 
 
A = 1.0*A;    
B = .5*B;     
D = (1/3)*D;     
D_top = (1/3)*D_top;     
D_bot = (1/3)*D_bot; 
 D_0 = (1/3)*D_0;     
D_90 = (1/3)*D_90; 
M(:,:,j) = (D_bot-D_top)./(D_0-D_90); 
end
end 
if is_crossply     
posMi = find(M>=0);     
negMi = find(M<=0);     
posM = polar(theta_rad(posMi),M(posMi));     
hold on;     
negM = polar(theta_rad(negMi),M(negMi)); 
set(posM , ...'Color','r',...'LineWidth',2)
set(negM , ...'Color','b',...'LineWidth',2,...'LineStyle','--')
title('Bending Stiffness Mismatch, M')
hold off;
if animate        
for i = 1:2:length(M)             
subplot(1,2,1) 
t = 0 : .01 : 2 * pi;             
P = polar(t, 1 * ones(size(t))); 
hold on; 
anim = polar(theta_rad(i),M(i)); 
hold on;             
[X,Y] = pol2cart(theta_rad(i),M(i));             
str = ['  \leftarrow ',num2str(M(i))];             
Mtext = text(X,Y,str); 
posM = polar(theta_rad(posMi),M(posMi)); 
hold on; 
negM = polar(theta_rad(negMi),M(negMi)); 
hold on; 
set(P, 'Visible', 'off')             
set(anim,...'Marker','o',...'MarkerSize',10)
set(Mtext,...'FontSize',16)
set(posM , ...'Color','r',...'LineWidth',2) 
set(negM , ...'Color','b',...'LineWidth',2,...'LineStyle','--')             
title('Bending Stiffness Mismatch, M')             
hold off;
subplot(1,2,2) 
xdir = [1;0];             
ydir = [0;1];             
R = [ cos(theta_rad(i))  -sin(theta_rad(i)) ;                   
sin(theta_rad(i))   cos(theta_rad(i))];             
xp = R*xdir;             
yp = R*ydir; 
xpaxis = plot([0 xp(1)],[0 xp(2)]); 
hold on;             
ypaxis = plot([0 yp(1)],[0 yp(2)]); 
hold on;             
xfixed = plot([0 1],[0 0]); 
hold on;             
yfixed = plot([0 0],[0 1]); 
hold on; 
xpaxis_text = text(xp(1),xp(2),'   x''');             
ypaxis_text = text(yp(1),yp(2),'   y''');             
xfixed_text = text(1,0,'   x');             
yfixed_text = text(0,1,'   y');             
angle_text = text(1,1,['\theta = ',num2str(theta(i))]); 
set(xpaxis,...'LineWidth',2,...'Color','green')             
set(ypaxis,...'LineWidth',2,...'Color','magenta')             
set(xfixed,...'LineWidth',2,...'Color','black')             
set(yfixed,...'LineWidth',2,...'Color','black')             
axis([-1.5 1.5 -1.5 1.5])             
axis square             
axis off             
title('Current Coordinate System')             
hold off;             
pause(an_speed)         
end     
end 
end
if is_crossply ~= 1
Mrs = reshape(M(1,1,:),[1,length(theta)]); 
t = 0 : .01 : 2 * pi; 
P = polar(t, 1 * ones(size(t))); 
hold on; 
posMi = find(Mrs>=0); 
negMi = find(Mrs<=0); 
posM = polar(theta_rad(posMi),Mrs(posMi)); 
hold on; 
negM = polar(theta_rad(negMi),Mrs(negMi)); 
hold on; 
set(P, 'Visible', 'off') 
set(posM , ...'Color','r',...'LineWidth',2) 
set(negM , ...'Color','b',...'LineWidth',2,...'LineStyle','--')
title('Bending Stiffness Mismatch, M') \
hold off; 
end
line 14 and 85 shows that the statement cannot be reached. Kindly help.

Best Answer

Those warnings are very simple to understand by aligning the code and looking at the values.
MATLAB warns you that lines 14 and 85 will never run, the reason is because you define the if condition to be zero:
is_crossply = 0;
...
if is_crossply
	M = cosd(2*theta); % line 14
else
...
if is_crossply
     posMi = find(M>=0); % line 85
     ....
If the condition is zero, how do you expect those lines to run?
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