plot.py 文件源码

def index_bar(ax, vals, facecolor='b', edgecolor='l', width=4, alpha=1.0, ):
    """Add a bar collection graph with height vals (-1 is missing).

    Parameters
    ----------
    ax : `Axes`
        an Axes instance to plot to
    vals : sequence
        a sequence of values
    facecolor : color
        the color of the bar face
    edgecolor : color
        the color of the bar edges
    width : int
        the bar width in points
    alpha : float
       bar transparency

    Returns
    -------
    ret : `barCollection`
        The `barrCollection` added to the axes

    """

    facecolors = (mcolors.to_rgba(facecolor, alpha),)
    edgecolors = (mcolors.to_rgba(edgecolor, alpha),)

    right = width / 2.0
    left = -width / 2.0

    bars = [((left, 0), (left, v), (right, v), (right, 0))
            for v in vals if v != -1]

    sx = ax.figure.dpi * (1.0 / 72.0)  # scale for points
    sy = ax.bbox.height / ax.viewLim.height

    barTransform = Affine2D().scale(sx, sy)

    offsetsBars = [(i, 0) for i, v in enumerate(vals) if v != -1]

    barCollection = PolyCollection(bars,
                                   facecolors=facecolors,
                                   edgecolors=edgecolors,
                                   antialiaseds=(0,),
                                   linewidths=(0.5,),
                                   offsets=offsetsBars,
                                   transOffset=ax.transData,
                                   )
    barCollection.set_transform(barTransform)

    minpy, maxx = (0, len(offsetsBars))
    miny = 0
    maxy = max([v for v in vals if v != -1])
    corners = (minpy, miny), (maxx, maxy)
    ax.update_datalim(corners)
    ax.autoscale_view()

    # add these last
    ax.add_collection(barCollection)
    return barCollection