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local_outlier_factor

Functions related to calculating the local outlier factor of a dataset.

local_outlier_factor(dataframe, k=20, geometry=None, approximate_knn=False, handle_ties=False, use_spheroid=False, result_column_name='lof')

Annotates a dataframe with a column containing the local outlier factor for each data record.

The dataframe should contain at least one GeometryType column. Rows must be unique. If one geometry column is present it will be used automatically. If two are present, the one named 'geometry' will be used. If more than one are present and neither is named 'geometry', the column name must be provided.

Parameters:

Name Type Description Default
dataframe DataFrame

apache sedona idDataframe containing the point geometries

required
k int

number of nearest neighbors that will be considered for the LOF calculation

20
geometry Optional[str]

name of the geometry column

None
approximate_knn bool

whether to use approximate KNN. When false will use exact KNN join. Default is False

False
handle_ties bool

whether to handle ties in the k-distance calculation. Default is false

False
use_spheroid

whether to use a cartesian or spheroidal distance calculation. Default is false

False
result_column_name str

the name of the column containing the lof for each row. Default is "lof"

'lof'

Returns:

Type Description

A PySpark DataFrame containing the lof for each row