Add explanatory comment for annotation box example

mollyrossow · mollyrossow · commit c4bfd1541640 · 2019-01-15T11:49:27.000-06:00
diff --git a/examples/text_labels_and_annotations/demo_annotation_box.py b/examples/text_labels_and_annotations/demo_annotation_box.py
@@ -1,9 +1,14 @@
-"""
-===================
+"""===================
 Demo Annotation Box
 ===================
 
+The AnnotationBbox Artist creates an annotation using an OffsetBox. This
+example demonstrates three different OffsetBoxes: TextArea, DrawingArea and
+OffsetImage. AnnotationBbox gives more fine-grained control than using the axes
+method annotate.
+
 """
+
 import matplotlib.pyplot as plt
 import numpy as np
 
@@ -95,3 +100,23 @@
 ax.set_ylim(0, 1)
 
 plt.show()
+
+#############################################################################
+#
+# ------------
+#
+# References
+# """"""""""
+#
+# The use of the following functions, methods and classes is shown in this
+# example:
+
+Circle
+TextArea
+DrawingArea
+OffsetImage
+AnnotationBbox
+get_sample_data
+plt.subplots
+plt.imread
+plt.show
