x<-runif(100,0,10)      # generate 100 random uniforms between 0 and 10
y<-1 + 2*x + rnorm(100) # generate some y's based on a simple 
                        # linear regression model
plot(x,y)               # Scatter plot of the data
fit<-lsfit(x,y)         # Least Squares fit (regression)
                        # Note: we are storing the results of the LS fit
                        # in the variable fit ... it will be used in several
                        # other steps.
ls.print(fit)           # Standard regression output
abline(fit)             # Add the regression line to the scatter plot
plot(x,fit$residuals)   # residual vs predictor plot
abline(h=0,lty=2)       # add a dashed horizontal line at y=0