Regression functions
Contrasts can be specified in the regression models with the following functions:
Comparisons amongst the levels of a factor
Polynomial contrasts of factor levels or of variate values
Contrasts specified by a matrix of coefficients for factors or by a
transposed data matrix for variates, also orthogonal polynomials
Smoothing of explanatory variates in a linear or generalized linear model can be specified by the
function:
Locally weighted regression effect of a variate (synonym LO)
Smoothing spline effect of a variate (synonym S)