TaskClassif
Classification Task
This task specializes Task and TaskSupervised for classification problems.
The target column is assumed to be a factor.
The task_type
is set to "classif"
.
Predefined tasks are stored in the Dictionary mlr_tasks.
- Keywords
- datasets
Format
R6::R6Class object inheriting from Task/TaskSupervised.
Construction
t = TaskClassif$new(id, backend, target, positive = NULL)
id
::character(1)
Identifier for the task.backend
:: DataBackend Either a DataBackend, or any object which is convertible to a DataBackend withas_data_backend()
. E.g., adata.frame()
will be converted to a DataBackendDataTable.target
::character(1)
Name of the target column.positive
::character(1)
Only for binary classification: Name of the positive class.
Fields
All methods from TaskSupervised, and additionally:
class_names
::character()
Returns all class labels of the target column.class_n
::integer(1)
Returns the number of classes.negative
::character(1)
Stores the negative class for binary classification tasks, andNA
for multiclass tasks.positive
::character(1)
Stores the positive class for binary classification tasks, andNA
for multiclass tasks.
Methods
See TaskSupervised.
See Also
Example classification task: iris
.
Other Task: TaskRegr
,
TaskSupervised
, Task
,
mlr_generators
, mlr_tasks
Examples
# NOT RUN {
data("Sonar", package = "mlbench")
task = TaskClassif$new("sonar", backend = Sonar, target = "Class", positive = "M")
task$task_type
task$formula()
task$truth()
task$class_names
task$positive
task$negative
# possible properties:
mlr_reflections$task_properties$classif
# }