library(gamair)
# Load our data
data(chicago)
# Make a scatter-plot of deaths per day versus temperature
# Many (5114) small filled-in points
plot(death ~ tmpd, data=chicago, pch=16, cex=0.2,
xlab="Mean daily temperature (Farenheit)",
ylab="Deaths per day")
# Run a linear regression
death.lm <- lm(death ~ tmpd, data=chicago)
summary(death.lm)
abline(death.lm)
# Exercise 1:
#### How would our prediction for any given day change if the temperture increased
#### by 5 degrees? Can you give the _average_ change over all days?
library(FNN)
# If the test argument isn't a column matrix, knn.reg() gets unhappy
death.30nn <- knn.reg(train=chicago$tmpd, test=matrix(chicago$tmpd, ncol=1),
y=chicago$death, k=30)
# Put temperatures in a nice order for plotting
lines(x=sort(chicago$tmpd), y=death.30nn$pred[order(chicago$tmpd)], lwd=3,
col="blue")
# Exercise 2:
#### How would our prediction for any given day change if the temperature
#### increased by 5 degrees? What calculation would you need to do?