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Convert to a Classification Task

Source: R/as_task_classif.R
as_task_classif.Rd

Convert object to a TaskClassif. This is a S3 generic. mlr3 ships with methods for the following objects:

  1. TaskClassif: returns the object as-is, possibly cloned.

  2. formula, data.frame(), matrix(), and DataBackend: provides an alternative to the constructor of TaskClassif.

  3. TaskRegr: Calls convert_task().

Note that the target column will be converted to a factor(), if possible.

Usage

as_task_classif(x, ...)

# S3 method for class 'TaskClassif'
as_task_classif(x, clone = FALSE, ...)

# S3 method for class 'data.frame'
as_task_classif(
  x,
  target,
  id = deparse1(substitute(x)),
  positive = NULL,
  label = NA_character_,
  ...
)

# S3 method for class 'matrix'
as_task_classif(
  x,
  target,
  id = deparse1(substitute(x)),
  label = NA_character_,
  ...
)

# S3 method for class 'DataBackend'
as_task_classif(
  x,
  target,
  id = deparse1(substitute(x)),
  positive = NULL,
  label = NA_character_,
  ...
)

# S3 method for class 'TaskRegr'
as_task_classif(
  x,
  target,
  drop_original_target = FALSE,
  drop_levels = TRUE,
  ...
)

# S3 method for class 'formula'
as_task_classif(
  x,
  data,
  id = deparse1(substitute(data)),
  positive = NULL,
  label = NA_character_,
  ...
)

Arguments

x

(any)
Object to convert.

...

(any)
Additional arguments.

clone

(logical(1))
If TRUE, ensures that the returned object is not the same as the input x.

target

(character(1))
Name of the target column.

id

(character(1))
Id for the new task. Defaults to the (deparsed and substituted) name of the data argument.

positive

(character(1))
Level of the positive class. See TaskClassif.

label

(character(1))
Label for the new instance.

drop_original_target

(logical(1))
If FALSE (default), the original target is added as a feature. Otherwise the original target is dropped.

drop_levels

(logical(1))
If TRUE (default), unused levels of the new target variable are dropped.

data

(data.frame())
Data frame containing all columns referenced in formula x.

Value

TaskClassif.

Examples

as_task_classif(palmerpenguins::penguins, target = "species")
#> 
#> ── <TaskClassif> (344x8) ───────────────────────────────────────────────────────
#> • Target: species
#> • Target classes: Adelie (44%), Gentoo (36%), Chinstrap (20%)
#> • Properties: multiclass
#> • Features (7):
#>   • int (3): body_mass_g, flipper_length_mm, year
#>   • dbl (2): bill_depth_mm, bill_length_mm
#>   • fct (2): island, sex