ldf: LDF Outlier score calculation

Description Usage Arguments Value See Also Examples

View source: R/outlier_lof.R

Description

ldf returns the LDF Outlier score for every observation in the given data_matrix. Kernel density estimation in combination with the reachability concept of LOF is used to calculate outlier score.

Usage

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ldf(data_matrix, k, h = 1, c = 0.1)

Arguments

data_matrix

numeric Matrix containing data the outlier score is calculated for. Rows are treated as observations, columns as features.

k

Number. Neighbourhood-size used to calculate outlier scores.

h

Number. Bandwidth scaling factor. Defaults to ELKI's default (1).

c

Number. Scaling constant to limit value range to 1/c. Defaults to ELKI's default (0.1).

Value

List of outlier scores. The score at position x belongs to the observation given in row x of the original data_matrix.

See Also

https://elki-project.github.io/releases/release0.7.5/javadoc/de/lmu/ifi/dbs/elki/algorithm/outlier/lof/LDF.html for ELKI documentation.

Examples

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data_matrix <- matrix(c(1:30), nrow=10, ncol=3)
result      <- ldf(data_matrix, 3)
for(index in c(1:10)) {
    print(paste('Observation:', paste(data_matrix[index,], collapse=',')))
    print(paste('Score:',       result[index]))
}

lenaWitterauf/rElki documentation built on June 2, 2020, 9:24 p.m.