message: case n_centers = 1
diff: @@ -672,6 +672,11 @@ class Atol(BaseEstimator, TransformerMixin):
  measures_concat = np.concatenate(X)
  self.quantiser.fit(X=measures_concat, sample_weight=sample_weight)
  self.centers = self.quantiser.cluster_centers_
  + if self.quantiser.n_clusters == 1:
  + dist_centers = pairwise.pairwise_distances(measures_concat)
  + np.fill_diagonal(dist_centers, 0)
  + self.inertias = np.max(dist_centers)/2
  + else:
  dist_centers = pairwise.pairwise_distances(self.centers)
  np.fill_diagonal(dist_centers, np.inf)
  self.inertias = np.min(dist_centers, axis=0)/2
  