AirEntrain is a categorical (yes/no) variable and cannot be used in regression without transforming it to a numerical {0,1} dummy/indicator variable. We can use our recoding skills from Lesson 5 to do ...

Any set of hyperplanes partitions E n into a set of polyhedra. A multivariate spline of degree n is a polynomial of total degree n on each polyhedron with all partial derivatives of order n - 1 being ...