def _is_plottable(structure):
    """ Determines if a PDS4 structure is plottable.

    Plottable structures are either:
        (1) 1D arrays, or
        (2) Tables

    Parameters
    ----------
    structure : Structure
        PDS4 structure to check.

    Returns
    -------
    bool
        True if *structure* can be plotted, False otherwise.
    """

    plottable = False

    if structure.is_table():
        plottable = True

    elif structure.is_array() and structure.meta_data.num_axes() == 1:
        plottable = True

    return plottable