print("You need to input a starting point from which to propagate!\n(even if displacement is zero)")
exit()
ifargs.GUIDING_POINTS_FILEisNone:
# You really need a start point...
ifargs.START_POINT_DISP[0:3]==[-1,-1,-1]:
print("You need to input a starting point from which to propagate!\n(even if displacement is zero)")
exit()
# If we have no out dir specified, deliver on our default promise -- this can't be done inline before since parser.parse_args() has not been run at that stage.