Repository: scikit-learn/scikit-learn
File: sklearn/ensemble/_iforest.py (Python)

Code before:
        .. versionadded:: 1.0

    See Also
    --------
    sklearn.covariance.EllipticEnvelope : An object for detecting outliers in a
        Gaussian distributed dataset.
    sklearn.svm.OneClassSVM : Unsupervised Outlier Detection.
        Estimate the support of a high-dimensional distribution.
        The implementation is based on libsvm.
    sklearn.neighbors.LocalOutlierFactor : Unsupervised Outlier Detection
        using Local Outlier Factor (LOF).

    Notes
    -----
    The implementation is based on an ensemble of ExtraTreeRegressor. The
    maximum depth of each tree is set to ``ceil(log_2(n))`` where
    :math:`n` is the number of samples used to build the tree
    (see [1]_ for more details).

    References
    ----------
    .. [1] Liu, Fei Tony, Ting, Kai Ming and Zhou, Zhi-Hua.
           :doi:`"Isolation forest." <10.1109/ICDM.2008.17>`
           2008 Eighth IEEE International Conference on Data Mining (ICDM),
           2008, pp. 413-422.
    .. [2] Liu, Fei Tony, Ting, Kai Ming and Zhou, Zhi-Hua.
           :doi:`"Isolation-based anomaly detection."
           <10.1145/2133360.2133363>` ACM Transactions on
           Knowledge Discovery from Data (TKDD) 6.1 (2012): 1-39.

    Examples
    --------
    >>> from sklearn.ensemble import IsolationForest
    >>> X = [[-1.1], [0.3], [0.5], [100]]
    >>> clf = IsolationForest(random_state=0).fit(X)
    >>> clf.predict([[0.1], [0], [90]])
    array([ 1,  1, -1])

    For an example of using isolation forest for anomaly detection see
    :ref:`sphx_glr_auto_examples_ensemble_plot_isolation_forest.py`.
    """

    _parameter_constraints: dict = {
        "n_estimators": [Interval(Integral, 1, None, closed="left")],
        "max_samples": [
            StrOptions({"auto"}),
            Interval(Integral, 1, None, closed="left"),
            Interval(RealNotInt, 0, 1, closed="right"),
        ],
        "contamination": [
            StrOptions({"auto"}),

Review comment (suggestion):
```suggestion
    .. [2] F. T. Liu, K. M. Ting and Z. -H. Zhou.
```

Code after:
        .. versionadded:: 1.0

    See Also
    --------
    sklearn.covariance.EllipticEnvelope : An object for detecting outliers in a
        Gaussian distributed dataset.
    sklearn.svm.OneClassSVM : Unsupervised Outlier Detection.
        Estimate the support of a high-dimensional distribution.
        The implementation is based on libsvm.
    sklearn.neighbors.LocalOutlierFactor : Unsupervised Outlier Detection
        using Local Outlier Factor (LOF).

    Notes
    -----
    The implementation is based on an ensemble of ExtraTreeRegressor. The
    maximum depth of each tree is set to ``ceil(log_2(n))`` where
    :math:`n` is the number of samples used to build the tree
    (see [1]_ for more details).

    References
    ----------
    .. [1] F. T. Liu, K. M. Ting and Z. -H. Zhou.
           :doi:`"Isolation forest." <10.1109/ICDM.2008.17>`
           2008 Eighth IEEE International Conference on Data Mining (ICDM),
           2008, pp. 413-422.
    .. [2] F. T. Liu, K. M. Ting and Z. -H. Zhou.
           :doi:`"Isolation-based anomaly detection."
           <10.1145/2133360.2133363>` ACM Transactions on
           Knowledge Discovery from Data (TKDD) 6.1 (2012): 1-39.

    Examples
    --------
    >>> from sklearn.ensemble import IsolationForest
    >>> X = [[-1.1], [0.3], [0.5], [100]]
    >>> clf = IsolationForest(random_state=0).fit(X)
    >>> clf.predict([[0.1], [0], [90]])
    array([ 1,  1, -1])

    For an example of using isolation forest for anomaly detection see
    :ref:`sphx_glr_auto_examples_ensemble_plot_isolation_forest.py`.
    """

    _parameter_constraints: dict = {
        "n_estimators": [Interval(Integral, 1, None, closed="left")],
        "max_samples": [
            StrOptions({"auto"}),
            Interval(Integral, 1, None, closed="left"),
            Interval(RealNotInt, 0, 1, closed="right"),
        ],
        "contamination": [
            StrOptions({"auto"}),