The levels of a factor are re-ordered so that the level specified by
ref is first and the others are moved down. This is useful for
contr.treatment contrasts which take the first level as the reference.
relevel(x, ref, ...)
- An unordered factor.
- The reference level.
- Additional arguments for future methods.
A factor of the same length as
Documentation reproduced from R 3.0.2. License: GPL-2.