index exceeds the matrix

for i=1:length(D)
        if (h_(i,T)~=D(i))
            eps(T)=eps(T)+D(i,:); 
        end  
    end

[dpb]

Insufficient information...

[Adam]

Don't use length(D) if D is a matrix, use size( D, 1 ) in that case. If the 2nd dimension of D happened to be larger than the first then this code would crash.

That may have nothing to do with your actual error, but as dpb says, you've given us next to no information to help with that apart from guessing and I only guess on a Tuesday.