def missing_dispersion(X, y=None, ax=None, classes=None, alpha=0.5, marker="|", **kwargs):
    """
    The Missing Values Dispersion visualizer shows the locations of missing (nan)
    values in the feature dataset by the order of the index.

    When y targets are supplied to fit, the output dispersion plot is color
    coded according to the target y that the element refers to.

    Parameters
    ----------
    alpha : float, default: 0.5
        A value for bending elments with the background.

    marker : matplotlib marker, default: |
        The marker used for each element coordinate in the plot

    classes : list, default: None
        A list of class names for the legend.
        If classes is None and a y value is passed to fit then the classes
        are selected from the target vector.

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

    Attributes
    ----------
    features_ : np.array
        The feature labels ranked according to their importance

    classes_ : np.array
        The class labels for each of the target values

    Examples
    --------

    >>> from yellowbrick.contrib.missing import missing_dispersion
    >>> visualizer = missing_dispersion(X, y=y)

    """
    # Instantiate the visualizer
    visualizer = MissingValuesDispersion(
        ax=ax, classes=classes, alpha=alpha, marker=marker, **kwargs
    )

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

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