#Creating a basic scatter plot	

attach(cars)
plot(speed,dist)

#Adding a regression line to a scatter plot

abline(lm(dist~speed))

#Making a scatter plot look good

attach(cars)
plot(speed,dist,main="Stopping Distance",xlab="Speed",ylab="Distance",pch=21,bg="red",col="red")

#Adding points to a scatter plot

read.table("cars2.txt",header=TRUE)
cars2=read.table("cars2.txt",header=TRUE)
attach(cars2)
points(Speed,Distance,col="blue", pch=21,bg="blue")

#Rescaling/Adding two data sets to a scatter plot

attach(cars)
cars2=read.table("cars2.txt",header=TRUE)
attach(cars2)
plot(c(speed,Speed),c(dist,Distance),xlab="Speed",ylab="Distance",main="Stopping Distances",type="n")
points(speed,dist,col="red",pch=21,bg="red")
points(Speed,Distance,col="blue",pch=21,bg="blue")


#Adding a Legend and regression lines to each data set

legend(locator(1),c("Car 1","Car 2"),pch=c(21,21),pt.bg=c("red","blue"),col=c("red","blue"))
abline(lm(Distance~Speed))
abline(lm(dist~speed))

#Loess Regression

attach(cars)
plot(speed,dist,main="Stopping Distance", xlab="Speed", ylab="Distance", pch=21, bg=2, col=2)
lines(lowess(cars, f=.3),col =1) 
lines(lowess(cars, f=.5),col =4)
lines(lowess(cars, f=.1),col =7)