Please explain the following line of code

Please explain the following line of code:

o(2.*[1:floor(D/2)]-1)=-32

where

o=-30+60*rand(1,D);

Answer 1

[Guillaume]

What couldn't you run the code and see what it does?

Your line of code is just a convoluted of doing:

o(1:2:end) = -32

which basically puts 32 in all the odd indices of o.

[Adnaan]

Could you please explain how does this code works, even if it is convoluted of doing o(1:2:end) = -32? D are number of dimensions that could 30 or 50.

[Guillaume]

There's nothing special about it. D is the length of o. The line creates the vector 1:floor(D/2) which is thus 1:floor(end/2) with respect to o. It them multiplies that vector by 2, so it makes the vector 2, 4, 6, ..., floor(end/2)*2 == end (or end-1). It then subtract 1 from that, so you get 1, 3, 5, ... end. That vector is then used to index o. Indexed values are assigned -32.

As I said, it just an inefficient and obscure way of doing:

o(1:2:end) = -32;

Don't use that original code. There is nothing useful about it.

[Adnaan]

Thank you very much indeed. I am trying to learn language. So, get stuck some times at such obscure codes. I am grate ful for your help.