title: Can't display bar plot with SHAP
body: <p>I'm new to SHAP and trying to use it on top of my RandomForestClassifier. Here's the code snippet after I already ran <code>clf.fit(train_x, train_y)</code>:</p>
  <pre><code>explainer = shap.Explainer(clf)
  shap_values = explainer(train_x.to_numpy()[0:5, :])
  shap.summary_plot(shap_values, plot_type='bar')
  </code></pre>
  <p>Here's the resulting plot:
  <a href="https://i.stack.imgur.com/p8Rvb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/p8Rvb.png" alt="enter image description here" /></a></p>
  <p>Now, there's two problems with this. One is that it is not a bar plot even though I set the <code>plot_type</code> parameter. The other is that I've seemed to lost my feature names somehow (and yes they do exist on the dataframes when calling <code>clf.fit()</code>).</p>
  <p>I tried replacing the last line with:</p>
  <pre><code>shap.summary_plot(shap_values, train_x.to_numpy()[0:5, :], plot_type='bar')
  </code></pre>
  <p>And that changed nothing. I also tried to replace it with the following to see if I could at least recover my feature names:</p>
  <pre><code>shap.summary_plot(shap_values, train_x.to_numpy()[0:5, :], feature_names=list(train_x.columns.values), plot_type='bar')
  </code></pre>
  <p>But that threw an error:</p>
  <pre><code>Traceback (most recent call last):
    File &quot;sklearn_model_runs.py&quot;, line 41, in &lt;module&gt;
      main()
    File &quot;sklearn_model_runs.py&quot;, line 38, in main
      shap.summary_plot(shap_values, train_x.to_numpy()[0:5, :], feature_names=list(train_x.columns.values), plot_type='bar')
    File &quot;C:\Users\kapoo\anaconda3\envs\sci\lib\site-packages\shap\plots\_beeswarm.py&quot;, line 554, in summary_legacy
      feature_names=feature_names[sort_inds],
  TypeError: only integer scalar arrays can be converted to a scalar index
  </code></pre>
  <p>I'm kind of at a loss at this point. I just tried it with 5 rows of the training set but want to use the whole thing once I get past this stumbling block. If it helps, the classifier had 5 labels and my SHAP version is 0.40.0.</p>