Yeah. So, it is like a graph we are use as rotating it, but you see if the now now, there is an interesting point suppose wind blows this side, you would expect most waves to be on this side, but you will also expect waves from the other side, but to an less extent ultimately you will expect almost 0 waves from 90 degree angle. So, this is how this idea of, what is called 3 D or they call short crested sea or short crested spectrum; where what they do is that what we assume is that look. The energy of all the waves are not only coming from direction one, but form all direction; however, the directional spread this is called spread is diminishing from the main direction and it will go to 0 as we go down.