def figs(self):
        """A mapping from figures to data objects with the plotter in this
        figure"""
        ret = utils.DefaultOrderedDict(lambda: self[1:0])
        for arr in self:
            if arr.psy.plotter is not None:
                ret[arr.psy.plotter.ax.get_figure()].append(arr)
        return OrderedDict(ret)
A mapping from figures to data objects with the plotter in this
        figure