errors in this code - 1D PDE with Boundary Condition

i am trying to solve ade and getting errors. plz help.

K = 0.15;
D = 100; 
U = 1;
dt = 0.005; dx = 1;
L = 10;
t = 50; T = 100;
c0 = 100; C0 = 100; %cin = 100mg/m^3
nx = 1+L/dx; nt = 1+t/dt;
c = zeros(nx,nt);
NT = 1+T/dt;
C = zeros(nx,NT);
c(1,:) = c0; C(1,:) = C0;

for k = 1:NT

     CN = U*dt/dx;

     DN = D*dt/dx^2;

     C(1,k) = c0;

     for i = 1:nx
         if (i == 1)

             C(i,k+1) = (2*DN)*c0+c(i,k+1)*(1-(2*DN)-(k*dt)-((DN-CN/2)*(2*dx*U/D)))+((DN-(CN/2)*(2*dx*c0*U/D)));

         elseif (i == nx)

             C(i,k+1) = 2*DN*c(i-1,k)+(1-2*DN-k*dt)*c(i,k);

         else

             C(i,k+1) = (DN+CN/2)*C(i-1,k) + (1-2*DN-K*dt)*C(i,k) +(DN-CN/2)*C(i+1,k);

         end

     end
  end

x = [0:dx:L];
plot(x,C(:,NT),'b');

return

Answer 1

[Matt Tearle]

I don't know exactly what you're trying to do with t and T (and associated nt and NT), but the result is that c and C have different numbers of columns. Your calculation of C(i,k+1) depends on c(i,k), and k runs from 1 to NT. Given that NT > nt, you end up referencing columns of c that don't exist -- ie k gets to nt+1 and then referencing c(i,k) must fail.

[tian]

yes exactly! my error message is this

??? Attempted to access c(1,10002); index out of

bounds because size(c)=[11,10001].

Error in ==> trying at 49

C(i,k) =.......

how to calculate in such a way that it calculates within matrix