step_ratio {recipes} | R Documentation |
step_ratio
creates a a specification of a recipe step that
will create one or more ratios out of numeric variables.
step_ratio(recipe, ..., role = "predictor", trained = FALSE, denom = denom_vars(), naming = function(numer, denom) make.names(paste(numer, denom, sep = "_o_")), columns = NULL) denom_vars(...)
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 will
be used in the numerator of the ratio. When used with
|
role |
For terms created by this step, what analysis role should they be assigned?. By default, the function assumes that the newly created ratios created by the original variables will be used as predictors in a model. |
trained |
A logical to indicate if the quantities for preprocessing have been estimated. |
denom |
A call to |
naming |
A function that defines the naming convention for new ratio columns. |
columns |
The column names used in the ratios. This argument is
not populated until |
An updated version of recipe
with the
new step added to the sequence of existing steps (if any).
library(recipes) data(biomass) biomass$total <- apply(biomass[, 3:7], 1, sum) biomass_tr <- biomass[biomass$dataset == "Training",] biomass_te <- biomass[biomass$dataset == "Testing",] rec <- recipe(HHV ~ carbon + hydrogen + oxygen + nitrogen + sulfur + total, data = biomass_tr) ratio_recipe <- rec %>% # all predictors over total step_ratio(all_predictors(), denom = denom_vars(total)) %>% # get rid of the original predictors step_rm(all_predictors(), -matches("_o_")) ratio_recipe <- prep(ratio_recipe, training = biomass_tr) ratio_data <- bake(ratio_recipe, biomass_te) ratio_data