title: missing 1 required positional argument for a function
body: <p>I am using Spyder IDE and call the following function in the Ipython shell after defining the input. But, I get the positional argument error! Perhaps something with the argument, but still I couldnt settle. can you help plz! Here is the code:</p>
  <pre><code>def get_confusion_matrix(label, ref_label, mask):
      label = sitk.GetArrayFromImage(label)
      ref_label = sitk.GetArrayFromImage(ref_label)
      mask = sitk.GetArrayFromImage(mask)
  
      ref_label[(mask == 2) &amp; (label &gt; 0)] = label[(mask == 2) &amp; (label &gt; 0)]
      ref_label[(mask == 1) &amp; (label == 0)] = 0
      return get_confusion_matrix(label.flatten(), ref_label.flatten())
  
  def get_dices(label, ref_label, mask):
      cm = get_confusion_matrix(label, ref_label, mask)
      dice_st = 2*cm[1,1]/(np.sum(cm[:,1]) + np.sum(cm[1,:]))
      dice_sv = 2*cm[2,2]/(np.sum(cm[:,2]) + np.sum(cm[2,:]))
      return dice_st, dice_sv
  </code></pre>
  <p>TypeError: get_confusion_matrix() missing 1 required positional argument: 'mask'</p>