Ch 7.1 Model object missing from code

[razzleh]

In chapter 7.1, the example code that produces figure 7.3, and the last line in the following block of code (printing a regression summary) call a model object mf which has not been defined in the code. Without this, it's not possible to follow along with the examples in 7.1.

[robjhyndman]

Thanks. Now fixed