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Predict_proba

As explained in Outlier Detection in Python

predict_proba is an estimator method that returns normalized class-membership scores for each supplied record.

predict_proba() returns a two-column array of normalized scores for each record: estimated inlier and outlier membership. In PyOD, these values are scaled scores rather than true probabilities, although they can be interpreted similarly. section 6.1

Interpret the method alongside the other common detector operations:

  • fit() trains the detector; predict() returns binary labels; decision_function() returns numeric outlier scores. section 6.1
  • By default, predict_proba() applies min-max scaling to decision_function() results, placing scores between 0.0 and 1.0. section 6.1
  • Each row contains inlier and outlier scores, which sum to 1.0; alternative scaling methods are available. section 6.1

How Outlier Detection in Python covers it

How deep it goes
Defines output shape and default scaling, but stops short of treating scores as calibrated probabilities.
Examples
Uses the common PyOD detector workflow with KNN and KDE examples.
What it assumes
Requires encoded categorical features, imputed missing values, and usually scaled numeric features.
What you can do after
Apply PyOD's method to obtain comparable inlier and outlier scores for each evaluated record.
How it connects
Connects fit(), predict(), decision_function(), binary labels, and outlier detection.

Related concepts

This explainer was generated by Manning's knowledge graph from the text of Outlier Detection in Python. The section links point to the parts of the book it draws on.