step_regex {recipes} | R Documentation |
step_regex
creates a specification of a recipe step that will
create a new dummy variable based on a regular expression.
step_regex(recipe, ..., role = "predictor", trained = FALSE, pattern = ".", options = list(), result = make.names(pattern), input = NULL)
recipe |
A recipe object. The step will be added to the sequence of operations for this recipe. |
... |
A single selector functions to choose which variable will be
searched for the pattern. The selector should resolve into a single
variable. See |
role |
For a variable created by this step, what analysis role should they be assigned?. By default, the function assumes that the new dummy variable column created by the original variable will be used as a predictors in a model. |
trained |
A logical to indicate if the quantities for preprocessing have been estimated. |
pattern |
A character string containing a regular expression (or
character string for |
options |
A list of options to |
result |
A single character value for the name of the new variable. It should be a valid column name. |
input |
A single character value for the name of the variable being
searched. This is |
An updated version of recipe
with the
new step added to the sequence of existing steps (if any).
data(covers) rec <- recipe(~ description, covers) %>% step_regex(description, pattern = "(rock|stony)", result = "rocks") %>% step_regex(description, pattern = "ratake families") rec2 <- prep(rec, training = covers) rec2 with_dummies <- bake(rec2, newdata = covers) with_dummies