Check Variable Class
check_class creates a specification of a recipe
check that will check if a variable is of a designated class.
check_class(
recipe,
...,
role = NA,
trained = FALSE,
class_nm = NULL,
allow_additional = FALSE,
skip = FALSE,
class_list = NULL,
id = rand_id("class")
)
## S3 method for class 'check_class'
tidy(x, ...)recipe |
A recipe object. The check will be added to the sequence of operations for this recipe. |
... |
One or more selector functions to choose which
variables are affected by the check. See |
role |
Not used by this check since no new variables are created. |
trained |
A logical to indicate if the quantities for preprocessing have been estimated. |
class_nm |
A character vector that will be used in |
allow_additional |
If |
skip |
A logical. Should the check be skipped when the
recipe is baked by |
class_list |
A named list of column classes. This is
|
id |
A character string that is unique to this step to identify it. |
x |
A |
This function can check the classes of the variables
in two ways. When the class argument is provided
it will check if all the variables specified are of the
given class. If this argument is NULL, the check will
learn the classes of each of the specified variables in prep.
Both ways will break bake if the variables are not of
the requested class. If a variable has multiple
classes in prep, all the classes are checked. Please note
that in prep the argument strings_as_factors defaults to
TRUE. If the train set contains character variables
the check will be break bake when strings_as_factors is
TRUE.
An updated version of recipe with the new check
added to the sequence of existing steps (if any). For the
tidy method, a tibble with columns terms (the
selectors or variables selected) and value (the type).
library(dplyr) library(modeldata) data(okc) # Learn the classes on the train set train <- okc[1:1000, ] test <- okc[1001:2000, ] recipe(train, age ~ . ) %>% check_class(everything()) %>% prep(train, strings_as_factors = FALSE) %>% bake(test) # Manual specification recipe(train, age ~ .) %>% check_class(age, class_nm = "integer") %>% check_class(diet, location, class_nm = "character") %>% check_class(date, class_nm = "Date") %>% prep(train, strings_as_factors = FALSE) %>% bake(test) # By default only the classes that are specified # are allowed. x_df <- tibble(time = c(Sys.time() - 60, Sys.time())) x_df$time %>% class() ## Not run: recipe(x_df) %>% check_class(time, class_nm = "POSIXt") %>% prep(x_df) %>% bake_(x_df) ## End(Not run) # Use allow_additional = TRUE if you are fine with it recipe(x_df) %>% check_class(time, class_nm = "POSIXt", allow_additional = TRUE) %>% prep(x_df) %>% bake(x_df)
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