update.step: Update a recipe step

In recipes: Preprocessing and Feature Engineering Steps for Modeling

Update a recipe step

Description

This step method for update() takes named arguments as ... who's values will replace the elements of the same name in the actual step.

Usage

## S3 method for class 'step'
update(object, ...)

Arguments

object	A recipe step.
...	Key-value pairs where the keys match up with names of elements in the step, and the values are the new values to update the step with.

Details

For a step to be updated, it must not already have been trained. Otherwise, conflicting information can arise between the data returned from bake(object, new_data = NULL) and the information in the step.

Examples

data(biomass, package = "modeldata")

biomass_tr <- biomass[biomass$dataset == "Training", ]
biomass_te <- biomass[biomass$dataset == "Testing", ]

# Create a recipe using step_bs() with degree = 3
rec <- recipe(
  HHV ~ carbon + hydrogen + oxygen + nitrogen + sulfur,
  data = biomass_tr
) %>%
  step_bs(carbon, hydrogen, degree = 3)

# Update the step to use degree = 4
rec2 <- rec
rec2$steps[[1]] <- update(rec2$steps[[1]], degree = 4)

# Prep both recipes
rec_prepped <- prep(rec, training = biomass_tr)
rec2_prepped <- prep(rec2, training = biomass_tr)

# To see what changed
bake(rec_prepped, new_data = NULL)
bake(rec2_prepped, new_data = NULL)

# Cannot update a recipe step that has been trained!
## Not run: 
update(rec_prepped$steps[[1]], degree = 4)

## End(Not run)

recipes documentation built on Aug. 26, 2023, 1:08 a.m.