recipes package can be used to create design matrices for modeling
and to conduct preprocessing of variables. It is meant to be a more
extensive framework that R's formula method. Some differences between
simple formula methods and recipes are that
Variables can have arbitrary roles in the analysis beyond predictors and outcomes.
A recipe consists of one or more steps that define actions on the variables.
Recipes can be defined sequentially using pipes as well as being modifiable and extensible.
recipe() defines the operations on the data and the associated
roles. Once the preprocessing steps are defined, any parameters are
prep(). Once the data are ready for
bake() function applies the operations.
These functions are used to add new actions to the recipe and have the
"step_action". For example,
step_center() centers the data to have a zero mean and
step_dummy() is used to create dummy variables.