# RPD -- Examples 1.1+ -- Soybean Yield vs. Ozone Level

yld.oz <- data.frame(ozone = c(0.02, 0.07, 0.11, 0.15),
                     yield = c(242, 237, 231, 201))
  # create a "data frame" object containing the data set

print(yld.oz)

yld.oz.model <- lm(yield ~ ozone, data=yld.oz)

summary(yld.oz.model)    # estimates, etc.
anova(yld.oz.model)      # analysis of variance
predict(yld.oz.model)    # predicted values
residuals(yld.oz.model)  # residuals

plot(yield ~ ozone, pch="x", xlim=c(0,0.16), ylim=c(190,260), data=yld.oz)
                                        # plot the points ...
abline(yld.oz.model)                    # and the fitted line