PdfPages在Matplotlib保存同一圖兩次

Question

下面的代碼提供in the matplotlib documentation創建Hinton的圖：

def hinton(matrix, max_weight=None, ax=None): 
    """Draw Hinton diagram for visualizing a weight matrix.""" 
    ax = ax if ax is not None else plt.gca() 

    if not max_weight: 
     max_weight = 2 ** np.ceil(np.log(np.abs(matrix).max())/np.log(2)) 

    ax.patch.set_facecolor('gray') 
    ax.set_aspect('equal', 'box') 
    ax.xaxis.set_major_locator(pl.NullLocator()) 
    ax.yaxis.set_major_locator(pl.NullLocator()) 

    for (x, y), w in np.ndenumerate(matrix): 
     color = 'white' if w > 0 else 'black' 
     size = np.sqrt(np.abs(w)/max_weight) 
     rect = pl.Rectangle([x - size/2, y - size/2], size, size, 
          facecolor=color, edgecolor=color) 
     ax.add_patch(rect) 

    ax.autoscale_view() 
    ax.invert_yaxis() 

我想創建兩個Hinton的圖表：一個用於權重從輸入要隱藏層，和一個從我的單層MLP中的隱藏層到輸出層。我曾嘗試（based on this jupyter notebook）：

W = model_created.layers[0].kernel.get_value(borrow=True) 
W = np.squeeze(W) 
print("W shape : ", W.shape) # (153, 15) 

W_out = model_created.layers[1].kernel.get_value(borrow=True) 
W_out = np.squeeze(W_out) 
print('W_out shape : ', W_out.shape) # (15, 8) 

with PdfPages('hinton_again.pdf') as pdf: 
    h1 = hinton(W) 
    h2 = hinton(W_out) 
    pdf.savefig() 

我也曾嘗試（based on this answer）：

h1 = hinton(W) 
h2 = hinton(W_out) 

pp = PdfPages('hinton_both.pdf') 
pp.savefig(h1) 
pp.savefig(h2) 
pp.close() 

無論如何，結局都是一樣的：W的韓丁圖繪製得到兩次。我怎樣才能在我的第一套權重中加入欣頓圖，並在同一pdf中加入我的第二組權重的欣頓圖（如果我能得到兩張欣頓圖，我還將解決兩個單獨的pdf）？

Answer 1

pdf.savefig()命令保存當前的數字。由於只有一個當前數字，它會將其保存兩次。爲了得到兩個數字，他們需要被創建，例如，通過plt.figure(1)和plt.figure(2)。

with PdfPages('hinton_again.pdf') as pdf: 
    plt.figure(1) 
    h1 = hinton(W) 
    pdf.savefig() 
    plt.figure(2) 
    h2 = hinton(W_out) 
    pdf.savefig() 

當然也有噸不同的方式來挽救兩個地塊，anotherone可能是

fig, ax = plt.subplots() 
hinton(W, ax=ax) 

fig2, ax2 = plt.subplots() 
hinton(W_out, ax=ax2) 

with PdfPages('hinton_again.pdf') as pdf: 
    pdf.savefig(fig) 
    pdf.savefig(fig2)