def _draw_circle(data, obj, draw_options):
    """Return the PGFPlots code for circles.
    """
    x, y = obj.center
    cont = "\\draw[%s] (axis cs:%.15g,%.15g) circle (%.15g);\n" % (
        ",".join(draw_options),
        x,
        y,
        obj.get_radius(),
    )
    return data, cont