Question:

In Lab3 where does the Xj term appear from in the equation near the bottom of the page? Also, what actually is it, it can't be the x vector from the training set as that is referred to as Xn. What does yn stand for? I know you mentioned this in the lecture but I'm unsure exactly what it is. Is it y(xn,w), y(xn,w)-tn or (y(xn,w)-tn)xj

Answer:

Sorry about the sloppy notation! its the jth element of the x vector (which is the nth example in the training set)

yn is the response to the nth input xn. tn is the target or desired response. yn is exactly the same as y(xn,w)