| contrasts {base} | R Documentation |
contrasts(x) contrasts(x) <- ctr
x |
a factor. |
ctr |
either a matrix whose columns give coefficients
for contrasts in the levels of x, or the (quoted)
name of a function which computes such matrices. |
These functions are used to set and view the
contrasts associated with a factor.
If contrasts are not set for a factor the default
functions from options("contrasts") are used.
C, contr.helmert, contr.poly,
contr.sum, contr.treatment,
glm, aov, lm.
example(factor) (fff <- factor(ff)) contrasts(fff) # treatment contrasts(C(fff, sum))