Implement a dialog to plot and export GPS data

Create a dialog with buttons to plot and export GPS data.

Show information about a GPS data point when user clicks on it.

#19 (closed)

sohstationviewer/model/mseed/mseed.py

@@ -351,7 +351,7 @@ class MSeed(DataTypeModel):
 
         # If location data is missing, we set them to 0.
         if gps_status_lines[5] == 'Latitude: ':
-            return GPSPoint(last_timemark, fix_type, 0, 0, 0, 0)
+            return GPSPoint(last_timemark, fix_type, 0, 0, 0, 0, '')
 
         num_sats_used = int(gps_status_lines[8].split(': ')[1])