hi guys, thanks for all your good words
I was not complaining, just trying to avoid other people the same experience. I'm here for the trip, which has been a lot of fun so far, and, yes, I've found that the exercises are invaluable in checking and improving one's understanding of the material. I clearly need to work on my maths. My grasp of the concept of orthogonal functions, which seems to be central here, is poor. One thing is sure, I found myself a new source of brain excitement that's going to keep me on my toes for quite a while
