I am trying to understand lagged correlations. 
 
x= 1:100; 
y = c(rep(NA,40), 1:60)ccf(x = x, y = y, lag.max=100, na.action=na.pass, type = "correlation") 
 
I was hoping to see max cor at lag = 40. But I am not. What am I doing wrong?
 
Thanks
VN
	[[alternative HTML version deleted]]