"Linda" wrote in message <email@example.com>... > hi all, > > i'm sure this is a simple one but i'm not sure how to do this the most efficient way in matlab: i have a vector x=[2.5;3.456];. how do i extrapolate this vector so that it hits the intercept? or find the intercept in a different way? is there a simple function for that? > > any help is appreciated.