diff --git a/kmeans.py b/kmeans.py
index db26e69..94d48c4 100644
--- a/kmeans.py
+++ b/kmeans.py
@@ -19,6 +19,7 @@
 sns.lmplot("x", "y", data=df, fit_reg=False, size=7)
 plt.show()
 vectors = tf.constant(vector_values)
+# choose the first num_clusters points as centroids
 centroids = tf.Variable(tf.slice(tf.random_shuffle(vectors), 
                                  [0,0],[num_clusters,-1]))
 expanded_vectors = tf.expand_dims(vectors, 0)