as_task_classif_st function

Convert to a Spatiotemporal Classification Task

Convert an object to a TaskClassifST . This is a S3 generic for the following objects:

1. TaskClassifST : Ensure the identity.
2. data.frame() and mlr3::DataBackend : Provides an alternative to the constructor of TaskClassifST .
3. sf::sf : Extracts spatial meta data before construction.
4. mlr3::TaskRegr : Calls mlr3::convert_task().

as_task_classif_st(x, ...)

## S3 method for class 'TaskClassifST'
as_task_classif_st(x, clone = FALSE, ...)

## S3 method for class 'data.frame'
as_task_classif_st(
  x,
  target,
  id = deparse(substitute(x)),
  positive = NULL,
  coordinate_names,
  crs = NA_character_,
  coords_as_features = FALSE,
  label = NA_character_,
  ...
)

## S3 method for class 'DataBackend'
as_task_classif_st(
  x,
  target,
  id = deparse(substitute(x)),
  positive = NULL,
  coordinate_names,
  crs,
  coords_as_features = FALSE,
  label = NA_character_,
  ...
)

## S3 method for class 'sf'
as_task_classif_st(
  x,
  target = NULL,
  id = deparse(substitute(x)),
  positive = NULL,
  coords_as_features = FALSE,
  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))

  Only for binary classification: Name of the positive class. The levels of the target columns are reordered accordingly, so that the first element of $class_names is the positive class, and the second element is the negative class.

• coordinate_names: (character(1))

  The column names of the coordinates in the data.

• crs: (character(1))

  Coordinate reference system. WKT2 or EPSG string.

• coords_as_features: (logical(1))

  If TRUE, coordinates are used as features. This is a shortcut for task$set_col_roles(c("x", "y"), role = "feature") with the assumption that the coordinates in the data are named "x" and "y".

• label: (character(1))

  Label for the new instance. Shown in as.data.table(mlr_tasks).

Returns

TaskClassifST .

Examples

if (mlr3misc::require_namespaces(c("sf"), quietly = TRUE)) {
  library("mlr3")
  data("ecuador", package = "mlr3spatiotempcv")

  # data.frame
  as_task_classif_st(ecuador, target = "slides", positive = "TRUE",
    coords_as_features = FALSE,
    crs = "+proj=utm +zone=17 +south +datum=WGS84 +units=m +no_defs",
    coordinate_names = c("x", "y"))

  # sf
  ecuador_sf = sf::st_as_sf(ecuador, coords = c("x", "y"), crs = 32717)
  as_task_classif_st(ecuador_sf, target = "slides", positive = "TRUE")
}