Anomalies above/below threshold

metadata.json

{
  "name": "Anomalies above threshold",
  "kind": "script",
  "description": "Creates an anomaly detector and a dataset with all the anomalies above or below a given threshold",
  "source_code": "script.whizzml",
  "inputs":[
    {
      "name": "dataset",
      "type": "dataset-id",
      "description": "Anomaly to use"
    },
    {
      "name": "threshold",
      "type": "number",
      "description": "Anomaly score threshold (0-100)"
    },
    {
      "name": "above",
      "type": "boolean",
      "default": false,
      "description": "If true, keep anomalies above threshold, below otherwise"
    }
  ],
  "outputs":[
    {
      "name": "anomaly",
      "type": "anomaly-id",
      "description": "The anomaly detector"
    },
    {
      "name": "dataset",
      "type": "dataset-id",
      "description": "Dataset with instances with a score above or below `threshold`"
    }]
}

script.whizzml

(define (batch-threshold dataset threshold above?)
  (when (not (<= 0 threshold 100))
    (raise "Threshold must be in the range [0, 100]"))
  (let (anomaly (create-anomaly dataset)
        ba (create-batchanomalyscore anomaly
                                     dataset
                                     {"output_dataset" true "all_fields" true})
        ds (resource-property (wait ba) "output_dataset_resource")
        th (/ threshold 100)
        cmp (if above? ">" "<")
        fltr (flatline "({cmp} (f \"score\") {th})")
        fds (wait (create-dataset ds {"lisp_filter" fltr})))
    (delete* [ba ds])
    [anomaly fds]))

(define [anomaly dataset] (batch-threshold dataset threshold above))