Resolve "Image creation bugs with 0 size windows"

Closes #21 (closed)

skais/ais/ais_trajectory.py

@@ -49,9 +49,10 @@ def apply_time_sequence(dat, time, func):
 
 
 class AISTrajectory(AISPoints):
-    def __init__(self, df, interpolation_time=None):
+    def __init__(self, df, mmsi=0, interpolation_time=None):
         df = df.drop_duplicates(subset=['ts_sec'])
         df = df.sort_values(by=['ts_sec'])
+        self.mmsi = mmsi
         if interpolation_time and len(df.index) > 4:
 
             float_columns = ['longitude', 'latitude', 'cog', 'heading', 'rot', 'sog', 'diff']