Stretching fails when dtt_lag='dynamic'

[asyates]

Just noticed that stretching fails when trying to resolve interstation distance using dynamic windows instead of static. Occurs because we are passing arguments station1 and station2 as strings into get_interstation_distance() function i.e.

pair = jobs[0].pair
ref_name = pair.replace(':', '_')
station1, station2 = pair.split(":")

if dtt_lag == "static":
      minlag = dtt_minlag
else:
      minlag = get_interstation_distance(station1, station2, station1.coordinates) / dtt_v

so station1.coordinates fails with error:

AttributeError: 'str' object has no attribute 'coordinates'

Will aim to correct today.