figrc.py 文件源码

def hinton(W, bg='grey', facecolors=('w', 'k')):
    """Draw a hinton diagram of the matrix W on the current pylab axis

    Hinton diagrams are a way of visualizing numerical values in a matrix/vector,
    popular in the neural networks and machine learning literature. The area
    occupied by a square is proportional to a value's magnitude, and the colour
    indicates its sign (positive/negative).

    Example usage:

        R = np.random.normal(0, 1, (2,1000))
        h, ex, ey = np.histogram2d(R[0], R[1], bins=15)
        hh = h - h.T
        hinton.hinton(hh)
    """
    M, N = W.shape
    square_x = np.array([-.5, .5, .5, -.5])
    square_y = np.array([-.5, -.5, .5, .5])

    ioff = False
    if plt.isinteractive():
        plt.ioff()
        ioff = True

    plt.fill([-.5, N - .5, N - .5, - .5], [-.5, -.5, M - .5, M - .5], bg)
    Wmax = np.abs(W).max()
    for m, Wrow in enumerate(W):
        for n, w in enumerate(Wrow):
            c = plt.signbit(w) and facecolors[1] or facecolors[0]
            plt.fill(square_x * w / Wmax + n, square_y * w / Wmax + m, c, edgecolor=c)

    plt.ylim(-0.5, M - 0.5)
    plt.xlim(-0.5, M - 0.5)

    if ioff is True:
        plt.ion()

    plt.draw_if_interactive()