recipes (version 0.1.1)

step_log: Logarithmic Transformation

Description

step_log creates a specification of a recipe step that will log transform data.

Usage

step_log(recipe, ..., role = NA, trained = FALSE, base = exp(1),
  columns = NULL)
# S3 method for step_log
tidy(x, ...)

Arguments

recipe

A recipe object. The step will be added to the sequence of operations for this recipe.

...

One or more selector functions to choose which variables are affected by the step. See selections() for more details. For the tidy method, these are not currently used.

role

Not used by this step since no new variables are created.

trained

A logical to indicate if the quantities for preprocessing have been estimated.

base

A numeric value for the base.

columns

A character string of variable names that will be (eventually) populated by the terms argument.

x

A step_log object.

Value

An updated version of recipe with the new step added to the sequence of existing steps (if any). For the tidy method, a tibble with columns terms (the columns that will be affected) and base.

See Also

step_logit() step_invlogit() step_hyperbolic() step_sqrt() recipe() prep.recipe() bake.recipe()

Examples

# NOT RUN {
set.seed(313)
examples <- matrix(exp(rnorm(40)), ncol = 2)
examples <- as.data.frame(examples)

rec <- recipe(~ V1 + V2, data = examples)

log_trans <- rec  %>%
  step_log(all_predictors())

log_obj <- prep(log_trans, training = examples)

transformed_te <- bake(log_obj, examples)
plot(examples$V1, transformed_te$V1)

tidy(log_trans, number = 1)
tidy(log_obj, number = 1)
# }