*x* Examples: Linear Models with Dummy Variables, R

Statistics 5102 (Geyer, Spring 2010) Examples: Linear Models with Dummy Variables: "Categorical Predictors and Dummy Variables
The subject of this web page is linear models in which some or all of the predictors are categorical. Special cases are called ANOVA and ANCOVA.
In principle, there is no problem. The model matrix is allowed to be any function whatsoever of the predictor variables (covariates).
In practice, we need to explain the most commonly used way in which the model matrix is made to depend on categorical covariates."