l=length(H);
for i=[1:l]
% dispersion relation to find wave length
[ka,L] = dispersion_relation(T(i),d);
That always uses corresponding H and T values. If you want the vectors to be independent then use another for loop such as
for i = 1 : length(H)
for iT = 1 : length(T)
[ka,L] = dispersion_relation(T(iT),d);
the other stuff
end
end
Depending exactly what you wanted to do, you might end up assigning to variables indexed at (i,iT) instead of at (i)
t=linspace(0,22);
That is a vector.
FT(i)=-Cm.*((pi.*rho.*D^2.*w^2.*H(i))./(8.*k)).*sin(w.*t)+Cd.*(rho.*D.*w^2.*H(i)^2)./(16.*sinh(k.*d)^2).*(((sinh(2.*k.*d))./(2.*k))+d).*cos(w.*t).*abs(cos(w.*t));
The right hand side uses the entire t vector in multiple places, so the right hand side is going to be a vector. But you are assigning the vector to a scalar location. You should do one of the following:
- assign to FT(i,:) or FT(:,i) so that each iteration you are recording one entry for every t value, into a 2D array (you might even want to go 3D if T is to be independent of H; OR
- assign to FT{i} instead of FT(i): cell arrays can hold multiple values for each index location; OR
- if the situation is mathematically suitable, use some kind of summarizing to transform the vector of values into a single value; for example sum() or var()
