Add docstring module to nichols.py

don4get · don4get · commit f4e3a1cf6906 · 2018-12-29T12:00:31.000+01:00
diff --git a/control/nichols.py b/control/nichols.py
@@ -1,3 +1,13 @@
+"""nichols.py
+
+Functions for plotting Black-Nichols charts.
+
+Routines in this module:
+
+nichols.nichols_plot aliased as nichols.nichols
+nichols.nichols_grid
+"""
+
 # nichols.py - Nichols plot
 #
 # Contributed by Allan McInnes <Allan.McInnes@canterbury.ac.nz>
