The recipes package is an alternative method for creating and preprocessing design matrices that can be used for modeling or visualization. From wikipedia:
In statistics, a design matrix (also known as regressor matrix or model matrix) is a matrix of values of explanatory variables of a set of objects, often denoted by X. Each row represents an individual object, with the successive columns corresponding to the variables and their specific values for that object.
While R already has long-standing methods for creating these matrices (e.g. formulas and model.matrix), there are some limitations to what the existing infrastructure can do.
The idea of the recipes package is to define a recipe or blueprint that can be used to sequentially define the encodings and preprocessing of the data (i.e. "feature engineering"). For example, to create a simple recipe containing only an outcome and predictors and have the predictors centered and scaled:
library(recipes)
library(mlbench)
data(Sonar)
sonar_rec <- recipe(Class ~ ., data = Sonar) %>%
step_center(all_predictors()) %>%
step_scale(all_predictors())The package is still in development and is not yet on CRAN. To install it, use:
if (packageVersion("devtools") < 1.6) {
install.packages("devtools")
}
devtools::install_github("topepo/recipes")