recipes (version 0.1.7)

update.step: 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 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 juice() and the information in the step.

Examples

# NOT RUN {
data(biomass)

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)

# Juice both to see what changed
juice(rec_prepped)
juice(rec2_prepped)

# Cannot update a recipe step that has been trained!
# }
# NOT RUN {
update(rec_prepped$steps[[1]], degree = 4)
# }
# NOT RUN {
# }