as_task_classif function

Convert to a Classification Task

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(), Matrix::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.

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 = NULL,
  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 'Matrix'
as_task_classif(
  x,
  target,
  id = deparse1(substitute(x)),
  label = NA_character_,
  ...
)

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

## S3 method for class 'TaskRegr'
as_task_classif(
  x,
  target = NULL,
  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.

Returns

TaskClassif .

Examples

as_task_classif(palmerpenguins::penguins, target = "species")