add threshold for graphs if refinment fails and edit annotate location

locklost/plugins/refine.py

@@ -67,11 +67,11 @@ def plot_indicators(event, channel, refined_gps, threshold):
             )
             ax1.annotate(
                 "threshold",
-                xy=(ax1.get_xlim()[0], threshold),
+                xy=(ax1.get_xlim()[-1], threshold),
                 xycoords='data',
-                xytext=(8, -15),
+                xytext=(8, -10),
                 textcoords='offset points',
-                horizontalalignment='left',
+                horizontalalignment='right',
                 verticalalignment='top',
                 bbox=dict(
                     boxstyle="round", fc="w", ec="green", alpha=0.95),
@@ -153,8 +153,8 @@ def find_transition(channel, segment, std_threshold, minimum=None):
     returns `threshold`, `refined_gps` tuple
 
     """
-    refined_gps = None
     threshold = None
+    refined_gps = None
     buf = data.fetch(channel, segment)[0]
 
     # calculate mean and std using first 5 seconds of window
@@ -191,9 +191,10 @@ def find_transition(channel, segment, std_threshold, minimum=None):
             logging.info("threshold: {}".format(threshold))
             logging.info("refined time: {}".format(refined_gps))
         else:
-            threshold = lower_threshold      # to be shown on graphs
             logging.info("no threshold crossings, unable to resolve time")
 
+    # add a threshold for graphs if no crossing found
+    threshold = lower_threshold if threshold is None else threshold
     return threshold, refined_gps