title: Clustering performance evaluation(Davies-Bouldin Index) error
body: <p>I am trying to figure out the optimum number of clusters using various clustering performance evaluation methods. I put my data through a loop and ran DBA k-means. I am getting the elbow and silhouette results but the dunn index is showing error. Below is the code:</p>
  <pre><code>inertias = []
  silhouette = []
  davies_bouldin = []
  clusters_range = range(1, 10)
      
  for K in clusters_range:
          dba_km = TimeSeriesKMeans(n_clusters=K,
                            n_init=2,
                            metric=&quot;dtw&quot;,
                            verbose=True,
                            max_iter_barycenter=10,
                            random_state=seed)
          y_pred = dba_km.fit_predict(scaled_ts)
          
          
          
          inertias.append(dba_km.inertia_)
          
          if K &gt; 1:
              silhouette.append(silhouette_score(scaled_ts, dba_km.labels_))
              
              davies_bouldin.append(davies_bouldin_score(scaled_ts, dba_km.labels_))
  </code></pre>
  <p>The error is showing on the <code>davies_bouldin.append</code> line:</p>
  <pre><code>TypeError: 'list' object is not callable.
  </code></pre>