MATLAB: Index in position 1 is invalid. Array indices must be positive integers or logical values.

Question

I got the problem that W is full of NaN's. Error is:

"Index in position 1 is invalid. Array indices must be positive integers or logical values.

Error in Seperationsansatz_2_lin_z (line 16) w(r,t) = W.*T;"

approach A*diff(w,r) + A*r*diff(w,r,r) -B*diff(w,t,t)
rspan = linspace(0,1);
W0 = [0; 1];
[r,W] = ode45(@odefct1,rspan, W0);
tspan = linspace(0,1);
T0 = [0;1];
[t,T] = ode45(@odefct2,tspan,T0);
w(r,t) = W.*T;
% plot(r,W(:,1),'-o',r,W(:,2),'-o')
% title('Solution');
% xlabel('Radius r');
% ylabel('Solution W');
% legend('W_1','W_2')
function dWdr = odefct1(r,W)
E = 70e7;
rho = 2.6989e-4;
ny = 0.34;
K = 1;
A = (0.5-ny);
B = rho*(1-2*ny)*(1+ny)/E;
dWdr = [ W(2); W(1)*(B*K)/A - W(2)/r];
end
function dTdt = odefct2(t,T)
K = 1;
dTdt = [T(2); K*T(1)];
end

Answer 1

This line:

w(r,t) = W.*T;

Replace with:

w = W.*T;