Why is this error occuring in my code.

Index exceeds matrix dimensions.

Error in test2 (line 20) C2(i) = B*log2(1+min(i));

Answer 1

[KL]

you're getting the error because you forgot to index B,

 C2(i) = B(i)*log2(1+min(i))

But anyway, what do you even mean by min(i), i in your case is just a scalar.

I'd recommend you to rename the loop varible , i, to something else since i is the default imaginary unit in matlab. Nextly, pre-allocate A, B, C2 and d properly. For example,

 A = zeros(1,length(ro_db))

TIP: when you see read underlines on your code, it means matlab is trying to help you by giving some warning and even recommendations, do not ignore them.

[Muneeb Ahmad]

Subscript indices must either be real positive integers or logicals.

Error in test2 (line 18) C2(i) = B*log2(1+(min(A,B)));

still getting this error others things are ok now.

[KL]

Again, you're not indexing A or B in your equation!

C2(i) = B(i)*log2(1+min(A(i),B(i)))