def plot_curve(curve, pen=None, shadow_pen=None, symbol="+",
               symbol_size=3, name=None):
    """
    Construct a `PlotCurve` for the given `ROCCurve`.

    :param ROCCurve curve:
        Source curve.

    The other parameters are passed to pg.PlotDataItem

    :rtype: PlotCurve
    """
    def extend_to_origin(points):
        "Extend ROCPoints to include coordinate origin if not already present"
        if points.tpr.size and (points.tpr[0] > 0 or points.fpr[0] > 0):
            points = ROCPoints(
                numpy.r_[0, points.fpr], numpy.r_[0, points.tpr],
                numpy.r_[points.thresholds[0] + 1, points.thresholds]
            )
        return points

    points = extend_to_origin(curve.points)
    item = pg.PlotCurveItem(
        points.fpr, points.tpr, pen=pen, shadowPen=shadow_pen,
        name=name, antialias=True
    )
    sp = pg.ScatterPlotItem(
        curve.points.fpr, curve.points.tpr, symbol=symbol,
        size=symbol_size, pen=shadow_pen,
        name=name
    )
    sp.setParentItem(item)

    hull = extend_to_origin(curve.hull)

    hull_item = pg.PlotDataItem(
        hull.fpr, hull.tpr, pen=pen, antialias=True
    )
    return PlotCurve(curve, item, hull_item)