new_contents: from os.path import join, expanduser
  
  from matplotlib.font_manager import FontProperties
  from mpl_toolkits.mplot3d import Axes3D
  import matplotlib.pyplot as plt
  from matplotlib import image
  
  from skimage.color import rgb2gray
  import numpy as np
  
  
  home = expanduser("~")
  font = FontProperties(fname=join(home, ".fonts", "ipag.ttf"), size=20)
  
  
  def plot(matrix, description):
      fig = plt.figure()
      ax = fig.add_subplot(111, projection='3d')
      assert(matrix.shape[0] == matrix.shape[1])
      N = matrix.shape[0]
  
      for i, row in enumerate(matrix):
          xs = np.arange(N)
  
          cs = row / np.max(matrix)
          zeros = np.zeros(len(cs))
          cs = np.vstack((cs, zeros, zeros)).T
          cs = 1 - np.abs(cs)
          ax.bar(xs, row, zs=i, zdir='y', color=cs, width=0.35, alpha=0.8)
  
      ax.set_xlabel('Row')
      ax.set_ylabel('Column')
      ax.set_zlabel('Value')
      ax.set_title(description, fontproperties=font)
      ax.view_init(30, 30)
      plt.show()
  
  matrix = np.loadtxt("dct")
  plot(matrix, 'DCTの結果 (サイズ: 120x120)')
  #image = image.imread("samp.bmp")
  #image = rgb2gray(image)
  #plot(image)
  
subject: Add plot