Finding intersections between 2 lines

FindIntersections

# https://stackoverflow.com/questions/20519431/finding-point-of-intersection-in-r

set.seed(1)
x1=rnorm(100,0,1)
x2=rnorm(100,1,1)
# Find points where x1 is above x2.
above<-x1>x2
# Points always intersect when above=TRUE, then FALSE or reverse
intersect.points<-which(diff(above)!=0)
# Find the slopes for each line segment.
x1.slopes<-x1[intersect.points+1]-x1[intersect.points]
x2.slopes<-x2[intersect.points+1]-x2[intersect.points]
# Find the intersection for each segment.
x.points<-intersect.points + ((x2[intersect.points] - x1[intersect.points]) / (x1.slopes-x2.slopes))
y.points<-x1[intersect.points] + (x1.slopes*(x.points-intersect.points))

plot(x1,type='l')
lines(x2,type='l',col='red')
points(x.points,y.points,col='blue')

x1[intersect.points]
x2[intersect.points]

setdiff(floor(x.points), intersect.points)