X轴在matplotlib中为固定大小（无法通过set_xlim更改）

Question

I'd like to remove part of the white part of the x-axis in the Hinton diagram that I'm plotting (see below). I've tried using ax1.set_xlim(1.5, width-4) , but that just moves the white space to the left side of the data. It would be easy to just fill up the white space with grey, but I'm not interested in doing that.

Even if I change the yaxis by using ax1.set_ylim(0, height) , the x-axis changes..

def _blob(x,y,area,colour):
    """
    Draws a square-shaped blob with the given area (< 1) at
    the given coordinates.
    """
    hs = np.sqrt(area) / 2
    xcorners = np.array([x - hs, x + hs, x + hs, x - hs])
    ycorners = np.array([y - hs, y - hs, y + hs, y + hs])
    P.fill(xcorners, ycorners, colour, edgecolor=colour)

def hinton(W, varLabels, maxWeight=None):
    """
    Draws a Hinton diagram for visualizing a weight matrix. 
    Temporarily disables matplotlib interactive mode if it is on, 
    otherwise this takes forever.
    """
    reenable = False
    if P.isinteractive():
        P.ioff()
    P.clf()
    height, width = W.shape
    if not maxWeight:
        maxWeight = 2**np.ceil(np.log(np.max(np.abs(W)))/np.log(2))

    fig  = plt.figure()  
    ax1  = fig.add_subplot(111) 
    ax1.set_xticks(np.arange(0,12))
    ax1.set_yticks(np.arange(0,12))
    ax1.tick_params(direction='inout')
    ax1.set_xticklabels(varLabels, rotation=45, ha='right')  
    ax1.set_yticklabels(["" for x in range(12)])    

    P.fill(np.array([0-0.5,width-0.5,width-0.5,0-0.5]),np.array([0-0.5,0-0.5,height,height]),'gray')
    #P.axis('off')
    P.axis('equal')
    for x in xrange(width):
        for y in xrange(height):
            _x = x+1
            _y = y+1
            w = W[y,x]
            if w > 0:
                _blob(_x - 1, height - _y + 0.5, min(1,w/maxWeight),'white')
            elif w < 0:
                _blob(_x - 1, height - _y + 0.5, min(1,-w/maxWeight),'black')
    ax1.set_xlim(1.5, width-1)
    if reenable:
        P.ion()
    P.show()


# Run the plot function
varLabels = ['n_contacts', 'n_calls', 'n_texts', 'dur_calls', 'morning', 'work-hours', 'evening', 'night', 'weekdays', 'friday', 'saturday', 'sunday']
hinton(conv_weights, varLabels)

Answer 1

Put

ax1.set_xlim(-0.5, width-0.5)
ax1.set_aspect('equal','box')

instead of

ax1.set_xlim(1.5, width-1)