def feature_importances(model, X, y=None, ax=None, labels=None,
                        relative=True, absolute=False, xlabel=None,
                        stack=False, **kwargs):
    """
    Displays the most informative features in a model by showing a bar chart
    of features ranked by their importances. Although primarily a feature
    engineering mechanism, this visualizer requires a model that has either a
    ``coef_`` or ``feature_importances_`` parameter after fit.

    Parameters
    ----------
    model : Estimator
        A Scikit-Learn estimator that learns feature importances. Must support
        either ``coef_`` or ``feature_importances_`` parameters.

    X : ndarray or DataFrame of shape n x m
        A matrix of n instances with m features

    y : ndarray or Series of length n, optional
        An array or series of target or class values

    ax : matplotlib Axes, default: None
        The axis to plot the figure on. If None is passed in the current axes
        will be used (or generated if required).

    labels : list, default: None
        A list of feature names to use. If a DataFrame is passed to fit and
        features is None, feature names are selected as the column names.

    relative : bool, default: True
        If true, the features are described by their relative importance as a
        percentage of the strongest feature component; otherwise the raw
        numeric description of the feature importance is shown.

    absolute : bool, default: False
        Make all coeficients absolute to more easily compare negative
        coeficients with positive ones.

    xlabel : str, default: None
        The label for the X-axis. If None is automatically determined by the
        underlying model and options provided.

    stack : bool, default: False
        If true and the classifier returns multi-class feature importance,
        then a stacked bar plot is plotted; otherwise the mean of the
        feature importance across classes are plotted.

    kwargs : dict
        Keyword arguments that are passed to the base class and may influence
        the visualization as defined in other Visualizers.

    Returns
    -------
    ax : matplotlib axes
        Returns the axes that the parallel coordinates were drawn on.
    """
    # Instantiate the visualizer
    visualizer = FeatureImportances(
        model, ax, labels, relative, absolute, xlabel, stack, **kwargs)

    # Fit and transform the visualizer (calls draw)
    visualizer.fit(X, y)
    visualizer.finalize()

    # Return the axes object on the visualizer
    return visualizer.ax