MATLAB: Why the code is not running

Question

m = 0;
x = linspace(0,1,41);
t = linspace(0,200,10);
sol = pdepe(m,@pdex5pde,@pdex5ic,@pdex5bc,x,t);
n = sol(:,:,1);
c = sol(:,:,2);
figure;
surf(x,t,c);
title('Distribution of fibronectin--c(x)');
xlabel('Distance x');
ylabel('Time t');
figure;
surf(x,t,n);
title('Distribution of ECs--n(x)');
xlabel('Distance x');
ylabel('Time t');
figure;
plot(x,n(end,:));
title('Final distribution of n(x).');
figure;
plot(x,c(end,:));
title('Final distribution of c(x).');
% --------------------------------------------------------------------------

function [c,f,s] = pdex5pde(x,t,u,DuDx)
d = 1e-3;
a = 3.8;
S = 3;
r = 0.88;
N = 1;
c = [1; 1];
f = [ d*DuDx(1) - a*u(1)*DuDx(2)
   DuDx(2)            ];
s1 = S*r*u(1)*(N - u(1));
s2 = S*(u(1)/(u(1) + 1) - u(2));
s = [s1; s2];
% --------------------------------------------------------------------------
function u0 = pdex5ic(x)
u0 = [1; 0.5];
if x >= 0.3 & x <= 0.6
   u0(1) = 1.05 * u0(1);
   u0(2) = 1.0005 * u0(2);
end

Answer 1

The pdex4 variable sol is a 9x13x2, or length(t) x length(x) x 2. The provided code (pdex5?) is 1x41x2. I don't understand your equations, but it looks like your code can't get past the t=0 step.

Can you double check that there is a solution at t=0?

It's worth verifying that your equations have been correctly entered as well.