The degree
values are returned as a character vector because they
should be treated categorically (as when plotting). Moreover, matrices
made with multiple vectors (e.g., poly(rnorm(10), rnorm(10), degree = 2)
)
have names that are not numerically meaningful (e.g., 1.0
, 2.0
, 0.1
,
1.1
, 0.2
),