# 
# Written by:
# -- 
# John L. Weatherwax                2009-04-21
# 
# email: wax@alum.mit.edu
# 
# Please send comments and especially bug reports to the
# above email address.
# 
#-----

library(alr3)
data(wm1)
attach(wm1)

# get an initial linear model using all data:
#
m = lm( CSpd ~ RSpd )

# perform a single prediction:
#
predict( m, newdata=data.frame(RSpd=7.4285), interval="prediction", level=0.95 )

# to get bootstrap predictions we need to create a function:
#

wwx_prediction_function <- function(m) {
predict( m,
	newdata=data.frame(RSpd=7.4285),
	interval="prediction", level=0.95 )[1]
}

pred.boot <- boot.case( m, B=999, f=wwx_prediction_function )

mean( pred.boot )
quantile( pred.boot, c(0.025,0.975) )