title: Plotting Multiclass ROC Curve
body: <p>I'm new to SciKit and Python.<br />
  Currently I am trying to generate a multiclass (3 classes) ROC curve from csv file that looks like this:</p>
  <pre><code>  probability,predclass,dist0,dist1,dist2,actualclass
    99.94571208953857,1,0.00022618949060415616,99.94571208953857,0.054055178770795465,1
    99.99398589134216,0,99.99398589134216,0.001082851395040052,0.004925658140564337,0
    99.97997879981995,1,0.015142260235734284,99.97997879981995,0.004879535117652267,1
    93.58544945716858,2,5.507804825901985,0.9067309089004993,93.58544945716858,2
    92.31788516044617,1,7.572370767593384,92.31788516044617,0.10974484030157328,1
    62.839555740356445,1,2.3740695789456367,62.839555740356445,34.786370396614075,2
          ... 
  </code></pre>
  <p>and my current code is:</p>
  <pre><code>df = pd.read_csv('mydata.csv')
  pred = (  df.loc[:,['dist0','dist1','dist2']])/100
  actual = df['actualclass']
  fpr, tpr, _ = roc_curve(actual, pred)
  </code></pre>
  <p>I have tried solution from this question: <a href="https://stackoverflow.com/a/45335434/14482749">https://stackoverflow.com/a/45335434/14482749</a></p>
  <p>by doing:</p>
  <pre><code>for i in range(n_classes):
      fpr[i], tpr[i], _ = roc_curve(actual, pred[:, i]) 
      roc_auc[i] = auc(fpr[i], tpr[i])
  </code></pre>
  <p>but received an error :  TypeError: '(slice(None, None, None), 0)' is an invalid key at line 2 above.</p>
  <p>I believe the problem is my var 'actual' but I am not sure what is it</p>