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Get and Set Contrast Matrices

Syntax

contrasts(x)
contrasts(x) <- ctr

Arguments

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.

Value

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 named the system options are used.

See Also

contr.helmert, contr.poly, contr.sum, contr.treatment, glm, lm.