Determine varying arguments

varying_args() takes a model specification or a recipe and returns a tibble of information on all possible varying arguments and whether or not they are actually varying.

# S3 method for model_spec
varying_args(object, full = TRUE, ...)

# S3 method for recipe
varying_args(object, full = TRUE, ...)

# S3 method for step
varying_args(object, full = TRUE, ...)

Arguments

object	A model_spec or a recipe.
full	A single logical. Should all possible varying parameters be returned? If FALSE, then only the parameters that are actually varying are returned.
...	Not currently used.

Value

A tibble with columns for the parameter name (name), whether it contains any varying value (varying), the id for the object (id), and the class that was used to call the method (type).

Details

The id column is determined differently depending on whether a model_spec or a recipe is used. For a model_spec, the first class is used. For a recipe, the unique step id is used.

Examples

# List all possible varying args for the random forest spec
rand_forest() %>% varying_args()
#> # A tibble: 3 x 4
#>   name  varying id          type      
#>   <chr> <lgl>   <chr>       <chr>     
#> 1 mtry  FALSE   rand_forest model_spec
#> 2 trees FALSE   rand_forest model_spec
#> 3 min_n FALSE   rand_forest model_spec

# mtry is now recognized as varying
rand_forest(mtry = varying()) %>% varying_args()
#> # A tibble: 3 x 4
#>   name  varying id          type      
#>   <chr> <lgl>   <chr>       <chr>     
#> 1 mtry  TRUE    rand_forest model_spec
#> 2 trees FALSE   rand_forest model_spec
#> 3 min_n FALSE   rand_forest model_spec

# Even engine specific arguments can vary
rand_forest() %>%
  set_engine("ranger", sample.fraction = varying()) %>%
  varying_args()
#> # A tibble: 4 x 4
#>   name            varying id          type      
#>   <chr>           <lgl>   <chr>       <chr>     
#> 1 mtry            FALSE   rand_forest model_spec
#> 2 trees           FALSE   rand_forest model_spec
#> 3 min_n           FALSE   rand_forest model_spec
#> 4 sample.fraction TRUE    rand_forest model_spec

# List only the arguments that actually vary
rand_forest() %>%
  set_engine("ranger", sample.fraction = varying()) %>%
  varying_args(full = FALSE)
#> # A tibble: 1 x 4
#>   name            varying id          type      
#>   <chr>           <lgl>   <chr>       <chr>     
#> 1 sample.fraction TRUE    rand_forest model_spec

rand_forest() %>%
  set_engine(
    "randomForest",
    strata = Class,
    sampsize = varying()
  ) %>%
  varying_args()
#> # A tibble: 5 x 4
#>   name     varying id          type      
#>   <chr>    <lgl>   <chr>       <chr>     
#> 1 mtry     FALSE   rand_forest model_spec
#> 2 trees    FALSE   rand_forest model_spec
#> 3 min_n    FALSE   rand_forest model_spec
#> 4 strata   FALSE   rand_forest model_spec
#> 5 sampsize TRUE    rand_forest model_spec