allow title to be None in _update_plot_title (fixes markov.py crash)

murrayrm · murrayrm · commit 1a04541004ed · 2024-08-08T17:19:17.000-07:00
diff --git a/control/ctrlplot.py b/control/ctrlplot.py
@@ -519,7 +519,7 @@ def _make_legend_labels(labels, ignore_common=False):
 
 def _update_plot_title(
         title, fig=None, frame='axes', use_existing=True, **kwargs):
-    if title is False:
+    if title is False or title is None:
         return
     if fig is None:
         fig = plt.gcf()
