def contour(h, axes=None, zoom=None, label_contour=False, **kwargs):
    """
    Draw a matplotlib contour plot from a 2D ROOT histogram.

    Parameters
    ----------

    h : Hist2D
        A rootpy Hist2D

    axes : matplotlib Axes instance, optional (default=None)
        The axes to plot on. If None then use the global current axes.

    zoom : float or sequence, optional (default=None)
        The zoom factor along the axes. If a float, zoom is the same for each
        axis. If a sequence, zoom should contain one value for each axis.
        The histogram is zoomed using a cubic spline interpolation to create
        smooth contours.

    label_contour : Boolean, optional (default=False)
        If True, labels are printed on the contour lines.

    kwargs : additional keyword arguments, optional
        Additional keyword arguments are passed directly to
        matplotlib's contour function.

    Returns
    -------

    Returns the value from matplotlib's contour function.

    """
    if axes is None:
        axes = plt.gca()
    x = np.array(list(h.x()))
    y = np.array(list(h.y()))
    z = np.array(h.z()).T
    if zoom is not None:
        from scipy import ndimage
        if hasattr(zoom, '__iter__'):
            zoom = list(zoom)
            x = ndimage.zoom(x, zoom[0])
            y = ndimage.zoom(y, zoom[1])
        else:
            x = ndimage.zoom(x, zoom)
            y = ndimage.zoom(y, zoom)
        z = ndimage.zoom(z, zoom)
    return_values = axes.contour(x, y, z, **kwargs)
    if label_contour:
        plt.clabel(return_values)
    return return_values
Draw a matplotlib contour plot from a 2D ROOT histogram.

    Parameters
    ----------

    h : Hist2D
        A rootpy Hist2D

    axes : matplotlib Axes instance, optional (default=None)
        The axes to plot on. If None then use the global current axes.

    zoom : float or sequence, optional (default=None)
        The zoom factor along the axes. If a float, zoom is the same for each
        axis. If a sequence, zoom should contain one value for each axis.
        The histogram is zoomed using a cubic spline interpolation to create
        smooth contours.

    label_contour : Boolean, optional (default=False)
        If True, labels are printed on the contour lines.

    kwargs : additional keyword arguments, optional
        Additional keyword arguments are passed directly to
        matplotlib's contour function.

    Returns
    -------

    Returns the value from matplotlib's contour function.