Shape · Statistics

Outlier Flag

Adds a true/false column marking rows with unusually high or low values. Rows are kept, so you can filter or review them afterwards.

Also known as: Anomaly flag

How it works

Pick the Columns to test and a Method. IQR flags a value below Q1 - k * IQR or above Q3 + k * IQR; Z-score flags a value whose distance from the mean, in sample standard deviations, exceeds k. Threshold is k, 1.5 by default, which suits IQR; 3 is the usual choice for Z-score. A row is flagged when any chosen column is an outlier. The flag is appended as is_outlier unless you set Output column; a column whose values are all equal flags nothing. No columns means no flag column is added.

Inputs and outputs

Settings

{
  columns: string[]
  method: "iqr"|"zscore"
  threshold: number
  outputColumn: string
}

Example

Find suspicious order amounts for review: columns amount, method Z-score, threshold 3, then a Filter on is_outlier = true.

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