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.
|
options("contrasts") are used.contr.helmert,contr.poly,
contr.sum,contr.treatment,
glm,lm.